This is a safety alert symbol and should never be ignored.
When you see this symbol on labels or in manuals, be alert
to the potential for personal injury or death.
WARNING
Improper installation, adjustment, alteration, service
or maintenance can cause property damage, person
al injury or loss of life. Installation and service must
be performed by a licensed professional installer (or
equivalent), service agency or the gas supplier.
AIR FLOW
AIR FLOW
HORIZONTAL LEFT
HORIZONTAL RIGHT
Table of Contents
Unit Dimensions2................................
EL296UHE Gas Furnace3.........................
Shipping and Packing List3........................
Unit Start Up49....................................
Gas Pressure Measurement50......................
Proper Combustion51..............................
High Altitude51....................................
Other Unit Adjustments53..........................
Sequence of Operation53..........................
Repair Parts List54................................
Service55........................................
Start-Up and Performance Checklist56...............
02/13
*2P0213*
Page 1
507067-01
*P507067-01*
Page 2
EL296UHE Unit Dimensions - inches (mm)
2
)
EXHAUST AIR
1
NOTE − 60C and 60D size units that require air
volumes 1800 cfm or over (850 L/s) must have
one of the following
1. Single side return air with transition, to accommodate
20 x 25 x 1 in. (508 x 635 x 25 mm) cleanable air
filter. Required to maintain proper air velocity.
2. Single side return air with optional Return Air Base
3. Bottom return air.
4. Return air from both sides.
5. Bottom and
See Blower Performance
2
Optional External Side Return Air Filter Kit is not for use
one side return air.
tables for additional information.
with the optional Return Air Base.
A
B
9/16 (14)
2
OPTIONAL
SIDE RETURN
AIR FILTER KIT
(Either Side)
14−3/4
(375)
16
(406)
33
(838)
COMBUSTION
AIR INTAKE
2
OPTIONAL
SIDE RETURN
AIR FILTER KIT
(Either Side)
1−1/2 (38)
Front Panel
6−9/16 (167)
9 (229)
12−5/8 (321)
(Either Side)
ELECTRICAL
INLET
(Either Side)
1−7/8 (48)
D
Left
Right
3−1/4
(83)
OUTLET
23−3/4
(603)
TOP VIEW
27−3/4
(705)
2 (51)
(Either Side)
GAS PIPING INLET
(Either Side)
CONDENSATE
TRAP CONNECTION
(Either Side)
6−1/2 (165)
(Either Side)
23
(584)
1
Side Return
Air Opening
(Either Side)
SUPPL Y AIR
OPENING
25
(635)
19−7/16
(494)
14
(356)
9/16
(14
1−1/
(38)
3/4
(19)
AIR FLOW
5/8
C
1
Bottom Return
Air Opening
3/4
(19)
(16)
3−1/4
(83)
23−1/2
(597)
1
Bottom Return
Air Opening
FRONT VIEWSIDE VIEW
Model No.
ABCD
in.mmin.mmin.mm
mmin.
EL296UH045XE36B
EL296UH070XE36B
EL296UH090XE48C
EL296UH110XE60C
EL296UH135XE60D
17−1/244616−3/8416164067−5/8194
2153319−7/850519−1/24959−3/8238
24−1/262223−3/85942358411−1/8283
Page 2
1−15/16 (49)
Page 3
EL296UHE Gas Furnace
Shipping and Packing List
The EL296UHE Category IV gas furnace is shipped ready
for installation in the upflow or horizontal position. The fur
nace is shipped with the bottom panel in place. The bot
tom panel must be removed if the unit is to be installed in
horizontal or upflow applications with bottom return air.
The EL296UHE can be installed as either a Direct Vent
or a Non-Direct Vent gas central furnace.
The furnace is equipped for installation in natural gas ap
plications. A conversion kit (ordered separately) is re
quired for use in propane/LP gas applications.
NOTE - In Direct Vent installations, combustion air is taken
from outdoors and flue gases are discharged outdoors. In
Non-Direct Vent installations, combustion air is taken from
indoors or ventilated attic or crawlspace and flue gases are
discharged outdoors. See figures 1 and 2 for applications in
volving roof termination.
DIRECT VENT INSTALLATIONNON-DIRECT VENT
EXHAUST OUTLET
COMBUSTION
AIR INTAKE OUTSIDE
OF HOUSE
INSTALLATION
EXHAUST
OUTLET
Package 1 of 1 contains
1 - Assembled EL296UHE unit
1 - Bag assembly containing the following:
1 - 3/4” Threaded street elbow
Check equipment for shipping damage. If you find any
damage, immediately contact the last carrier.
The following items may also be ordered separately:
1 - Thermostat
1 - LP/Propane changeover kit
1 - Return air base kit
1 - Horizontal suspension kit
1 - High altitude pressure switch
Safety Information
FIGURE 1
NON-DIRECT VENT
INSTALLATION
EXHAUST
OUTLET
COMBUSTION
AIR INTAKE INSIDE
VENTILATED
ATTIC SPACE
FIGURE 2
COMBUSTION
AIR INTAKE
OF HOUSE
NON-DIRECT VENT
INSTALLATION
EXHAUST
OUTLET
COMBUSTION
AIR INTAKE INSIDE
VENTILATED
CRAWL SPACE
INSIDE
CAUTION
As with any mechanical equipment, personal injury
can result from contact with sharp sheet metal
edges. Be careful when you handle this equipment.
DANGER
Danger of explosion.
There are circumstances in which odorant used with
LP/propane gas can lose its scent. In case of a leak,
LP/propane gas will settle close to the floor and may
be difficult to smell. An LP/propane leak detector
should be installed in all LP applications.
Use only the type of gas approved for use with this furnace.
Refer to unit nameplate.
EL296UHE units are CSA International certified to ANSI
Z21.47 and CSA 2.3 standards.
Building Codes
In the USA, installation of gas furnaces must conform with lo
cal building codes. In the absence of local codes, units must
be installed according to the current National Fuel Gas Code
(ANSI‐Z223.1/NFPA 54). The National Fuel Gas Code is
available from the following address:
American National Standards Institute, Inc.
11 West 42nd Street
New York, NY 10036
In Canada, installation must conform with current National
Standard of Canada CSA‐B149 Natural Gas and Propane
Installation Codes, local plumbing or waste water codes
and other applicable local codes.
Page 3
Page 4
In order to ensure proper unit operation in non-direct vent
applications, combustion and ventilation air supply must be
provided according to the current National Fuel Gas Code
or CSA‐B149 standard.
Heating Unit Installed Parallel to Air Handler Unit
Dampers
(open during heating operation only)
Installation Locations
This furnace is CSA International certified for installation
clearances to combustible material as listed on the unit
nameplate and in the table in figure 12. Accessibility and ser
vice clearances must take precedence over fire protection
clearances.
NOTE - For installation on combustible floors, the furnace
shall not be installed directly on carpeting, tile, or other
combustible material other than wood flooring.
For installation in a residential garage, the furnace must
be installed so that the burner(s) and the ignition source
are located no less than 18 inches (457 mm) above the
floor. The furnace must be located or protected to avoid
physical damage by vehicles. When a furnace is installed
in a public garage, hangar, or other building that has a haz
ardous atmosphere, the furnace must be installed accord
ing to recommended good practice requirements and cur
rent National Fuel Gas Code or CSA B149 standards.
NOTE - Furnace must be adjusted to obtain a temperature
rise within the range specified on the unit nameplate. Failure
to do so may cause erratic limit operation and premature heat
exchanger failure.
This EL296UHE furnace must be installed so that its
electrical components are protected from water.
Installed in Combination with a Cooling Coil
When this furnace is used with cooling coils (figure 3), it shall
be installed in parallel with, or on the upstream side of, cool
ing coils to avoid condensation in the heating compartment.
With a parallel flow arrangement, a damper (or other means
to control the flow of air) must adequately prevent chilled air
from entering the furnace. If the damper is manually oper
ated, it must be equipped to prevent operation of either the
heating or the cooling unit, unless it is in the full HEAT orCOOL setting.
When installed, this furnace must be electrically grounded
according to local codes. In addition, in the United States,
installation must conform with the current National Electric
Code, ANSI/NFPA No. 70. The National Electric Code
(ANSI/NFPA No. 70) is available from the following ad
dress:
National Fire Protection Association
1 Battery March Park
Quincy, MA 02269
In Canada, all electrical wiring and grounding for the unit
must be installed according to the current regulations of the
Canadian Electrical Code Part I (CSA Standard C22.1)
and/or local codes.
Gas Unit
AIR FLOWAIR FLOW
Air Handler Unit
Dampers
(open during cooling operation only)
Heating Unit Installed Upstream of Cooling Coil
AIR FLOWAIR FLOW
Cooling Coil
Gas Unit
FIGURE 3
NOTE - This furnace is designed for a minimum continu
ous return air temperature of 60°F (16°C) or an intermit
tent operation down to 55°F (13°C) dry bulb for cases
where a night setback thermostat is used. Return air tem
perature must not exceed 85°F (29°C) dry bulb.
The EL296UHE furnace may be installed in alcoves, clos
ets, attics, basements, garages, crawl spaces and utility
rooms in the upflow or horizontal position.
This furnace design has not been CSA certified for installa
tion in mobile homes, recreational vehicles, or outdoors.
Use of Furnace as Construction Heater
Lennox does not recommend the use of EL296UHE units
as a construction heater during any phase of construction.
Very low return air temperatures, harmful vapors and op
eration of the unit with clogged or misplaced filters will dam
age the unit.
EL296UHE units may be used for heating of buildings or
structures under construction, if the following conditions
are met:
D The vent system must be permanently installed per
these installation instructions.
D A room thermostat must control the furnace. The use of
fixed jumpers that will provide continuous heating is not
allowed.
D The return air duct must be provided and sealed to the
furnace.
D Return air temperature range between 60°F (16°C) and
80°F (27°C) must be maintained.
D Air filters must be installed in the system and must be
maintained during construction.
D Air filters must be replaced upon construction comple
tion.
Page 4
Page 5
D The input rate and temperature rise must be set per the
furnace rating plate.
D One hundred percent (100%) outdoor air must be pro
vided for combustion air requirements during construc
tion. Temporary ducting may supply outdoor air to the
furnace. Do not connect duct directly to the furnace.
Size the temporary duct following these instructions in
section for Combustion, Dilution and Ventilation Air in a
confined space with air from outside.
D The furnace heat exchanger, components, duct system,
air filters and evaporator coils must be thoroughly
cleaned following final construction clean-up.
D All furnace operating conditions (including ignition, in
put rate, temperature rise and venting) must be verified
according to these installation instructions.
General
These instructions are intended as a general guide and do
not supersede local codes in any way. Consult authorities
having jurisdiction before installation.
In addition to the requirements outlined previously, the fol
lowing general recommendations must be considered
when installing an EL296UHE furnace:
• Place the furnace as close to the center of the air dis
tribution system as possible. The furnace should also be
located close to the vent termination point.
• When the furnace is installed in non-direct vent applica
tions, do not install the furnace where drafts might blow
directly into it. This could cause improper combustion
and unsafe operation.
• When the furnace is installed in non-direct vent applica
tions, do not block the furnace combustion air opening
with clothing, boxes, doors, etc. Air is needed for proper
combustion and safe unit operation.
• When the furnace is installed in an attic or other insu
lated space, keep insulation away from the furnace.
• When the furnace is installed in an unconditioned
space, consider provisions required to prevent freezing
of condensate drain system.
• The “A” coil drain pan is high quality engineering poly
mer with a maximum service temperature of 500° F.
However, adequate space must be provided between
the drain pan and the furnace heat exchanger. At least
2” space is required for sectionalized heat exchanger
and and 4” for drum-type or oil-fired furnace exchanger.
Closer spacing may damage the drain pan and cause
leaking.
CAUTION
EL296UHE unit should not be installed in areas nor
mally subject to freezing temperatures.
WARNING
The State of California has determined that this prod
uct may contain or produce a chemical or chemicals,
in very low doses, which may cause serious illness
or death. It may also cause cancer, birth defects or
reproductive harm.
WARNING
Insufficient combustion air can cause headaches,
nausea, dizziness or asphyxiation. It will also cause
excess water in the heat exchanger resulting in rust
ing and premature heat exchanger failure. Excessive
exposure to contaminated combustion air will result
in safety and performance related problems. Avoid
exposure to the following substances in the com
bustion air supply:
Permanent wave solutions
Chlorinated waxes and cleaners
Chlorine base swimming pool chemicals
Water softening chemicals
De-icing salts or chemicals
Carbon tetrachloride
Halogen type refrigerants
Cleaning solvents (such as perchloroethylene)
Printing inks, paint removers, varnishes, etc.
Hydrochloric acid
Cements and glues
Antistatic fabric softeners for clothes dryers
Masonry acid washing materials
Combustion, Dilution & Ventilation Air
If the EL296UHE is installed as a Non-Direct Vent Fur
nace, follow the guidelines in this section.
NOTE - In Non-Direct Vent installations, combustion air
is taken from indoors or ventilated attic or crawlspace
and flue gases are discharged out-doors.
In the past, there was no problem in bringing in sufficient
outdoor air for combustion. Infiltration provided all the air
that was needed. In today's homes, tight construction
practices make it necessary to bring in air from outside
for combustion. Take into account that exhaust fans, ap
pliance vents, chimneys, and fireplaces force additional
air that could be used for combustion out of the house.
Unless outside air is brought into the house for combus
tion, negative pressure (outside pressure is greater than
inside pressure) will build to the point that a downdraft
can occur in the furnace vent pipe or chimney. As a result,
combustion gases enter the living space creating a po
tentially dangerous situation.
In the absence of local codes concerning air for combustion and ventilation, use the guidelines and procedures in
this section to install EL296UHE furnaces to ensure effi
cient and safe operation. You must consider combustion
air needs and requirements for exhaust vents and gas
Page 5
Page 6
piping. A portion of this information has been reprinted
with permission from the National Fuel Gas Code (ANSIZ223.1/NFPA 54). This reprinted material is not the com
plete and official position of the ANSI on the referenced
subject, which is represented only by the standard in its
entirety.
In Canada, refer to the CSA B149 installation codes.
CAUTION
Do not install the furnace in a corrosive or contami
nated atmosphere. Meet all combustion and ventila
tion air requirements, as well as all local codes.
All gas‐fired appliances require air for the combustion pro
cess. If sufficient combustion air is not available, the fur
nace or other appliance will operate inefficiently and un
safely. Enough air must be provided to meet the needs of all
fuel-burning appliances and appliances such as exhaust
fans which force air out of the house. When fireplaces, ex
haust fans, or clothes dryers are used at the same time as
the furnace, much more air is required to ensure proper
combustion and to prevent a downdraft. Insufficient air
causes incomplete combustion which can result in carbon
monoxide.
In addition to providing combustion air, fresh outdoor air di
lutes contaminants in the indoor air. These contaminants
may include bleaches, adhesives, detergents, solvents
and other contaminants which can corrode furnace compo
nents.
The requirements for providing air for combustion and ven
tilation depend largely on whether the furnace is installed in
an unconfined or a confined space.
Unconfined Space
Confined Space
A confined space is an area with a volume less than 50 cubic
feet (1.42 m
3
) per 1,000 Btu (.29 kW) per hour of the combined input rating of all appliances installed in that space. This
definition includes furnace closets or small equipment rooms.
When the furnace is installed so that supply ducts carry air
circulated by the furnace to areas outside the space con
taining the furnace, the return air must be handled by ducts
which are sealed to the furnace casing and which terminate
outside the space containing the furnace. This is especially
important when the furnace is mounted on a platform in a
confined space such as a closet or small equipment room.
Even a small leak around the base of the unit at the platform
or at the return air duct connection can cause a potentially
dangerous negative pressure condition. Air for combustion
and ventilation can be brought into the confined space ei
ther from inside the building or from outside.
Air from Inside
If the confined space that houses the furnace adjoins a
space categorized as unconfined, air can be brought in by
providing two permanent openings between the two
spaces. Each opening must have a minimum free area of 1
square inch (645 mm
2
) per 1,000 Btu (.29 kW) per hour of
total input rating of all gas-fired equipment in the confined
space. Each opening must be at least 100 square inches
(64516 mm
2
). One opening shall be within 12 inches (305
mm) of the top of the enclosure and one opening within 12
inches (305 mm) of the bottom. See figure 4.
EQUIPMENT IN CONFINED SPACE - ALL AIR FROM INSIDE
ROOF TERMINATED
EXHAUST PIPE
An unconfined space is an area such as a basement or
large equipment room with a volume greater than 50 cubic
feet (1.42 m
3
) per 1,000 Btu (.29 kW) per hour of the com
bined input rating of all appliances installed in that space.
This space also includes adjacent rooms which are not
separated by a door. Though an area may appear to be un
confined, it might be necessary to bring in outdoor air for
combustion if the structure does not provide enough air by
infiltration. If the furnace is located in a building of tight
construction with weather stripping and caulking around
the windows and doors, follow the procedures in the Air
from Outside section.
OPENINGS
SIDE WALL
TERMINATED
EXHAUST PIPE
(ALTERNATE
LOCATION)
NOTE - Each opening shall have a free area of at least one square inch
per 1,000 Btu (645mm
all equipment in the enclosure, but not less than 100 square inches
(64516mm.
2).
EL296UH
E
2
per .29kW) per hour of the total input rating of
(To Adjacent
Unconfined
Space)
FIGURE 4
Page 6
Page 7
Air from Outside
e
If air from outside is brought in for combustion and ventila
tion, the confined space shall be provided with two perma
nent openings. One opening shall be within 12” (305mm)
of the top of the enclosure and one within 12” (305mm) of
the bottom. These openings must communicate directly
or by ducts with the outdoors or spaces (crawl or attic) that
freely communicate with the outdoors or indirectly
through vertical ducts. Each opening shall have a mini
mum free area of 1 square inch per 4,000 Btu (645mm
per 1.17kW) per hour of total input rating of all equipment
in the enclosure (figures 5 and 8). When communicating
with the outdoors through horizontal ducts, each opening
shall have a minimum free area of 1 square inch per 2,000
2
Btu (645mm
per .59kW) per total input rating of all equip
ment in the enclosure (See figure 9). It is also permissible
to bring in air for combustion from a ventilated attic (figure
6) or ventilated crawl space (figure 7).
EQUIPMENT IN CONFINED SPACE - ALL AIR FROM OUTSIDE
(Inlet Air from Crawl Space and Outlet Air to Outside)
VENTILATION LOUVERS
OUTLET
AIR
(Each end of attic)
VENTILATION
LOUVERS
(For unheated
crawl space)
2
per 1.17kW) per
ROOF TERMINATED
EXHAUST PIPE
SIDE WALL
TERMINATED
EXHAUST PIPE
(ALTERNATE
LOCATION)
FURNACE
INLET
AIR
NOTE-The inlet and outlet air openings shall each have a free area
of at least one square inch per 4,000 Btu (645mm
hour of the total input rating of all equipment in the enclosure.
FIGURE 5
(Inlet Air from Ventilated Crawlspace and Outlet Air to Outside)
EQUIPMENT IN CONFINED SPACE
Roof T erminated
Exhaust Pipe
2
Inlet Air
(Minimum
Ventilation
Louvers
(Crawl space)
Coupling or
3 in. to 2 in.
Furnace
12 in.(305mm)
Above crawl
space floor)
*Intake Debris Screen Provided)
Transition
(Field Provided)
* See table 6 for maximum vent lengths
NOTE-The inlet and outlet air openings shall each have a free area
of at least one square inch per 4,000 Btu (645mm
hour of the total input rating of all equipment in the enclosure.
2
per 1.17kW) per
FIGURE 7
When ducts are used, they shall be of the same cross-sec
tional area as the free area of the openings to which they
connect. The minimum dimension of rectangular air ducts
shall be no less than 3 inches (75 mm). In calculating free
area, the blocking effect of louvers, grilles, or screens
must be considered. If the design and free area of protec
tive covering is not known for calculating the size opening
required, it may be assumed that wood louvers will have
20 to 25 percent free area and metal louvers and grilles
will have 60 to 75 percent free area. Louvers and grilles
must be fixed in the open position or interlocked with the
equipment so that they are opened automatically during
equipment operation.
(Inlet Air from Ventilated Attic and Outlet Air to Outside)
EQUIPMENT IN CONFINED SPACE
Ventilation Louvers
Roof T erminated
Exhaust Pipe
Inlet Air
(Minimum
12 in.(305mm) Abov
attic floor)
*Intake Debris
Screen
(Provided)
Furnace
* See table 6 for maximum vent lengths
NOTE-The inlet and outlet air openings shall each have a free area
of at least one square inch per 4,000 Btu (645mm
hour of the total input rating of all equipment in the enclosure.
2
per 1.17kW) per
FIGURE 6
Page 7
EQUIPMENT IN CONFINED SPACE - ALL AIR FROM OUTSIDE
(All Air Through Ventilated Attic)
ROOF TERMINATED
EXHAUST PIPE
OUTLET
AIR
SIDE WALL
TERMINATED
EXHAUST PIPE
(ALTERNATE
LOCATION)
FURNACE
NOTE-The inlet and outlet air openings shall each have a free area of
at least one square inch per 4,000 Btu (645mm
VENTILATION LOUVERS
(Each end of attic)
INLET AIR
(Ends 12” above
bottom)
2
per 1.17kW) per hour
of the total input rating of all equipment in the enclosure.
FIGURE 8
Page 8
EQUIPMENT IN CONFINED SPACE -
ALL AIR FROM OUTSIDE
Installation - Setting Equipment
ROOF TERMINATED
EXHAUST PIPE
OUTLET AIR
SIDE WALL
TERMINATED
EXHAUST PIPE
(ALTERNATE
LOCATION)
NOTE-Each air duct opening shall have a free area of at least one
square inch per 2,000 Btu (645mm
input rating of all equipment in the enclosure. If the equipment room
is located against an outside wall and the air openings communi
cate directly with the outdoors, each opening shall have a free area
of at least 1 square inch per 4,000 Btu (645mm
hour of the total input rating of all other equipment in the enclosure.
FURNACE
INLET AIR
2
per .59kW) per hour of the total
2
per 1.17kW) per
FIGURE 9
Shipping Bolt Removal
Units with 1/2 hp blower motor are equipped with three flex
ible legs and one rigid leg. The rigid leg is equipped with a
shipping bolt and a flat white plastic washer (rather than the
rubber mounting grommet used with a flexible mounting
leg). See figure 10. The bolt and washer must be removed before the furnace is placed into operation. Af
ter the bolt and washer have been removed, the rigid leg
will not touch the blower housing.
WARNING
Do not connect the return air duct to the back of the
furnace. Doing so will adversely affect the operation
of the safety control devices, which could result in
personal injury or death.
WARNING
Blower access panel must be securely in place when
blower and burners are operating. Gas fumes, which
could contain carbon monoxide, can be drawn into
living space resulting in personal injury or death.
Upflow Applications
The EL296UHE gas furnace can be installed as shipped
in the upflow position. Refer to figure 12 for clearances.
Select a location that allows for the required clearances
that are listed on the unit nameplate. Also consider gas
supply connections, electrical supply, vent connection,
condensate trap and drain connections, and installation
and service clearances [24 inches (610 mm) at unit
front]. The unit must be level from side to side. The unit
may be positioned from level to ½” toward the front. See
figure 11.
Allow for clearances to combustible materials as indicated
on the unit nameplate.
EL296 Furnaces with
1/2 HP Blower Motor
RIGID LEG
(Remove shipping bolt
and washer)
FIGURE 10
Page 8
Page 9
SETTING EQUIPMENT
UPFLOW APPLICATION
UNIT
FRONT
SIDE VIEW
AIR FLOW
FRONT VIEW
UNIT
FRONT
AIR FLOW
SIDE VIEW
1/2”
max.
HORIZONTAL APPLICATION
UNIT
FRONT
FRONT VIEW
AIR FLOW
END VIEW
1/2”
max.
Unit must be level side-to-side. Unit may be positioned from level to 1/2” toward the front to aid in draining.
FIGURE 11
Page 9
Page 10
WARNING
Improper installation of the furnace can result in per
sonal injury or death. Combustion and flue products
must never be allowed to enter the return air system
or air in the living space. Use sheet metal screws and
joint tape to seal return air system to furnace.
In platform installations with furnace return, the fur
nace should be sealed airtight to the return air ple
num. A door must never be used as a portion of the
return air duct system. The base must provide a
stable support and an airtight seal to the furnace. Al
low absolutely no sagging, cracks, gaps, etc.
For no reason should return and supply air duct sys
tems ever be connected to or from other heating de
vices such as a fireplace or stove, etc. Fire, explo
sion, carbon monoxide poisoning, personal injury
and/or property damage could result.
Installation Clearances
Top
Return Air Guidelines
Return air can be brought in through the bottom or either
side of the furnace installed in an upflow application. If the
furnace is installed on a platform with bottom return, make
an airtight seal between the bottom of the furnace and the
platform to ensure that the furnace operates properly and
safely. The furnace is equipped with a removable bottom
panel to facilitate installation.
Markings are provided on both sides of the furnace cabinet
for installations that require side return air. Cut the furnace
cabinet at the maximum dimensions shown on page 2.
Refer to Product Specifications for additional information.
EL296UHE applications which include side return air
and a condensate trap installed on the same side of the
cabinet (trap can be installed remotely within 5 ft.) re
quire either a return air base or field-fabricated transi
tion to accommodate an optional IAQ accessory taller
than 14.5”. See figure 13.
Left Side
Bottom (Floor)
Top/Plenum1 in. (25 mm)
*Front0
Back0
Sides0†
Vent0
Floor0‡
*Front clearance in alcove installation must be 24 in. (610 mm).
Maintain a minimum of 24 in. (610 mm) for front service access.
†Allow proper clearances to accommodate condensate trap.
‡For installations on a combustible floor, do not install the furnace
directly on carpeting, tile or other combustible materials other
than wood flooring.
Right Side
FIGURE 12
Side Return Air
(with transition and filter)
20” X 25” X 1”
(508mmX635mmX25mm)
1−1/2”
Air Filter
Return
Air
Plenum
Transition
FIGURE 13
Page 10
Page 11
)
FURNACE
FRONT
Optional Return Air Base
(Upflow Applications Only)
1
23 (584)
Overall
(Maximum)
1
Unit side return air
Opening
5−5/8
(143)
SIDE RETURN
AIR OPENINGS
(Either Side)
26−7/8
(683)
SIDE VIEW
23
(584)
1
Minimum
11 (279)
2
Maximum
14 (356)
1
22−7/16
(570)
Overall
(Maximum
3/4
(19)
AIR FLOW
17−1/2 (446) B Width (50W98)
21 (533) C Width (50W99)
24−1/2 (622) D Width (51W00)
INDOOR AIR
QUALITY
CABINET
(PCO, Filter
Cabinet, etc.)
OPTIONAL
RETURN
AIR BASE
IF BASE
IS USED
WITHOUT
IAQ CABINET,
A SINGLE
RETURN AIR
PLENUM
MUST
COVER BOTH
UNIT AND
RETURN
AIR BASE
OPENINGS
3−1/4
(83)
7−1/4
(184)
FRONT VIEW
NOTE- Optional side return air filter kits are not for use with return air base.
1
Both the unit return air opening and the base return air opening must be covered by a single plenum or IAQ cabinet.
Minimum unit side return air opening dimensions for units requiring 1800 cfm of air and over (W x H): 23 x 11 in. (584 x 279 mm).
The opening can be cut as needed to accommodate plenum or IAQ cabinet while maintaining dimensions shown.
Side return air openings must be cut in the field. There are cutting guides stenciled on the cabinet for the side return air
opening. The size of the opening must not extend beyond the markings on the furnace cabinet.
2
To minimize pressure drop, the largest opening height possible (up to 14 inches) is preferred.
FIGURE 14
Removing the Bottom Panel
Removing the Bottom Panel
Remove the two screws that secure the bottom cap to the
furnace. Pivot the bottom cap down to release the bottom
panel. Once the bottom panel has been removed, reinstall
the bottom cap. See figure 15.
Horizontal Applications
Screw
Bottom Panel
FIGURE 15
Bottom Cap
Page 11
WARNING
Do not install the furnace on its front or back.
See figure 16.
Front
FIGURE 16
Back
Page 12
The EL296UHE furnace can be installed in horizontal ap
plications with either right- or left-hand air discharge.
Refer to figure 17 for clearances in horizontal applications.
Horizontal Application
Installation Clearances
HORIZONTAL SUSPENSION KIT
Metal Strap
(typical)
Internal Brace
(provided with kit)
Right-Hand Discharge
Left EndRight End
Air
Flow
Bottom (Floor)**
Left-Hand Discharge
Top
Left EndRight End
Air
Flow
Bottom (Floor)**
Top0
Front*0
Back0
Ends0
Vent0
Floor0‡
*Front clearance in alcove installation must be 24 in. (610 mm).
Maintain a minimum of 24 in. (610 mm) for front service access.
**An 8” service clearance must be maintained below the unit to
provide for servicing of the condensate trap.
‡For installations on a combustible floor, do not install the furnace
directly on carpeting, tile or other combustible materials other
than wood flooring.
Air
Flow
Air
Flow
FIGURE 17
Suspended Installation of Horizontal Unit
This furnace may be installed in either an attic or a crawl
space. Either suspend the furnace from roof rafters or
floor joists, as shown in figure 18, or install the furnace on
a platform, as shown in figure 19. A horizontal suspension
kit (51W10) may be ordered from Lennox or use equiva
lent.
NOTE - Heavy-gauge sheet metal straps may be used to
suspend the unit from roof rafters or ceiling joists. When
straps are used to suspend the unit in this way, support
must be provided for both the ends. The straps must not
interfere with the plenum or exhaust piping installation.
Cooling coils and supply and return air plenums must
be supported separately.
Bracket
(typical)
Air
Flow
FIGURE 18
NOTE - When the furnace is installed on a platform or with
the horizontal suspension kit in a crawlspace, it must be
elevated enough to avoid water damage, accommodate
drain trap and to allow the evaporator coil to drain.
Platform Installation of Horizontal Unit
1 - Select location for unit keeping in mind service and
other necessary clearances. See figure 17.
2 - Construct a raised wooden frame and cover frame
with a plywood sheet. If unit is installed above finished
space, install an an auxiliary drain pan under unit. Set
unit in drain pan as shown in figure 19. Leave 8 inches
for service clearance below unit for condensate trap.
3 - Provide a service platform in front of unit. When instal
ling the unit in a crawl space, a proper support platform
may be created using concrete blocks.
4 - Route auxiliary drain line so that water draining from
this outlet will be easily noticed by the homeowner.
5 - If necessary, run the condensate line into a conden
sate pump to meet drain line slope requirements. The
pump must be rated for use with condensing furnaces.
Protect the condensate discharge line from the pump
to the outside to avoid freezing.
6 - Continue with exhaust, condensate and intake piping
installation according to instructions.
Page 12
Page 13
INTAKE PIPE
EXHAUST PIPE
*Gas connector may be
used for Canadian
installation if accept
able by local authority
having jurisdiction.
SERVICE PLATFORM
*GAS CONNECTION
RAISED
PLATFORM
FIGURE 19
Return Air -- Horizontal Applications
Return air may be brought in only through the end of a fur
nace installed in the horizontal position. The furnace is
equipped with a removable bottom panel to facilitate
installation. See figure 15.
Filters
This unit is not equipped with a filter or rack. A field-pro
vided high velocity rated filter is required for the unit to oper
ate properly. Table 1 lists recommended filter sizes.
A filter must be in place whenever the unit is operating.
IMPORTANT
If a highefficiency filter is being installed as part of
this system to ensure better indoor air quality, the fil
ter must be properly sized. Highefficiency filters
have a higher static pressure drop than standardef
ficiency glass/foam filters. If the pressure drop is too
great, system capacity and performance may be re
duced. The pressure drop may also cause the limit to
trip more frequently during the winter and the indoor
coil to freeze in the summer, resulting in an increase
in the number of service calls.
Before using any filter with this system, check the
specifications provided by the filter manufacturer
against the data given in the appropriate Lennox
Product Specifications bulletin. Additional informa
tion is provided in Service and Application Note
ACC002 (August 2000).
TABLE 1
Furnace
Cabinet Width
17-1/2”16 X 25 X 1 (1)16 X 25 X 1 (1)
21”16 X 25 X 1 (1)20 X 25 X 1 (1)
24-1/2”16 X 25 X 1 (2)24 X 25 X 1 (1)
Side ReturnBottom Return
Filter Size
Duct System
Use industry‐approved standards to size and install the
supply and return air duct system. Refer to ACCA Manual
D. This will result in a quiet and low‐static system that has
uniform air distribution.
NOTE - This furnace is not certified for operation in heating
mode (indoor blower operating at selected heating speed)
with an external static pressure which exceeds 0.8 inches
w.c. Operation at these conditions may result in improper
limit operation.
Supply Air Plenum
If the furnace is installed without a cooling coil, a removable
access panel should be installed in the supply air duct. The
access panel should be large enough to permit inspection
of the heat exchanger. The furnace access panel must al
ways be in place when the furnace is operating and it must
not allow leaks.
Return Air Plenum
NOTE - Return air must not be drawn from a room
where this furnace, or any other gas-fueled appliance
(i.e., water heater), or carbon monoxide-producing de
vice (i.e., wood fireplace) is installed.
When return air is drawn from a room, a negative pres
sure is created in the room. If a gas appliance is operating
in a room with negative pressure, the flue products can
be pulled back down the vent pipe and into the room. This
re verse flow of the flue gas may re sult in incompl ete com
bustion and the formation of carbon monoxide gas. This
raw gas or toxic fumes might then be distributed through
out the house by the furnace duct system.
Return air can be brought in through the bottom or either
side of the furnace (return air brought into either side of fur
nace allowed only in upflow applications). If a furnace with
bottom return air is installed on a platform, make an airtight
seal between the bottom of the furnace and the platform to
ensure that the unit operates properly and safely. Use fiber
glass sealing strips, caulking, or equivalent sealing method
between the plenum and the furnace cabinet to ensure a
tight seal. If a filter is installed, size the return air duct to fit
the filter frame.
Pipe & Fittings Specifications
All pipe, fittings, primer and solvent cement must conform
with American National Standard Institute and the Ameri
can Society for Testing and Materials (ANSI/ASTM) stan
dards. The solvent shall be free flowing and contain no
lumps, undissolved particles or any foreign matter that ad
versely affects the joint strength or chemical resistance of
the cement. The cement shall show no gelation, stratifica
tion, or separation that cannot be removed by stirring. Re
fer to the table 2 below for approved piping and fitting ma
terials.
Page 13
Page 14
CAUTION
Solvent cements for plastic pipe are flammable liq
uids and should be kept away from all sources of
ignition. Do not use excessive amounts of solvent
cement when making joints. Good ventilation should
be maintained to reduce fire hazard and to minimize
breathing of solvent vapors. Avoid contact of ce
ment with skin and eyes.
EL296UHE exhaust and intake connections are
made of PVC. Use PVC primer and solvent cement
when using PVC vent pipe. When using ABS vent
pipe, use transitional solvent cement to make con
nections to the PVC fittings in the unit.
Use PVC primer and solvent cement or ABS solvent cement
meeting ASTM specifications, refer to Table 2. As an alter
nate, use all purpose cement, to bond ABS, PVC, or CPVC
pipe when using fittings and pipe made of the same materi
als. Use transition solvent cement when bonding ABS to ei
ther PVC or CPVC.
Low temperature solvent cement is recommended during
installation in cooler weather. Metal or plastic strapping may
be used for vent pipe hangers. Uniformly apply a liberal coat
of PVC primer for PVC or use a clean dry cloth for ABS to
clean inside socket surface of fitting and male end of pipe to
depth of fitting socket.
Canadian Applications Only - Pipe, fittings, primer
and solvent cement used to vent (exhaust) this ap
pliance must be certified to ULC S636 and supplied by a
single manufacturer as part of an approved vent (ex
haust) system. In addition, the first three feet of vent
pipe from the furnace flue collar must be accessible for
inspection.
Joint Cementing Procedure
All cementing of joints should be done according to the
specifications outlined in ASTM D 2855.
DANGER
DANGER OF EXPLOSION!
Fumes from PVC glue may ignite during system
check. Allow fumes to dissipate for at least 5 minutes
before placing unit into operation.
1 - Measure and cut vent pipe to desired length.
2 - Debur and chamfer end of pipe, removing any ridges
or rough edges. If end is not chamfered, edge of pipe
may remove cement from fitting socket and result in a
leaking joint.
NOTE - Check the inside of vent pipe thoroughly for
any obstruction that may alter furnace operation.
3 - Clean and dry surfaces to be joined.
4 - Test fit joint and mark depth of fitting on outside of pipe.
5 - Uniformly apply a liberal coat of PVC primer for PVC or
use a clean dry cloth for ABS to clean inside socket
surface of fitting and male end of pipe to depth of fitting
socket.
NOTE - Time is critical at this stage. Do not allow prim
er to dry before applying cement.
6 - Promptly apply solvent cement to end of pipe and in
side socket surface of fitting. Cement should be ap
plied lightly but uniformly to inside of socket. Take
care to keep excess cement out of socket. Apply sec
ond coat to end of pipe.
7 - Immediately after applying last coat of cement to pipe,
and while both inside socket surface and end of pipe
are wet with cement, forcefully insert end of pipe into
socket until it bottoms out. Turn PVC pipe 1/4 turn dur
ing assembly (but not after pipe is fully inserted) to dis
tribute cement evenly. DO NOT turn ABS or cellular
core pipe.
NOTE - Assembly should be completed within 20 sec
onds after last application of cement. Hammer blows
should not be used when inserting pipe.
Page 14
Page 15
8 - After assembly, wipe excess cement from pipe at end
of fitting socket. A properly made joint will show a
bead around its entire perimeter. Any gaps may indi
cate an improper assembly due to insufficient sol
vent.
9 - Handle joints carefully until completely set.
Conduct the following test while each appliance is operat
ing and the other appliances (which are not operating) re
main connected to the common venting system. If the
venting system has been installed improperly, you must
correct the system as indicated in the general venting re
quirements section.
Venting Practices
Piping Suspension Guidelines
SCHEDULE 40
PVC - 5'
all other pipe* - 3'
* See table 2 for allowable pipe.
NOTE - Isolate piping at the point where it exits the outside wall or
roof in order to prevent transmission of vibration to the structure.
NOTE - All horizontal runs of exhaust pipe must slope back to
ward unit a minimum of 1/4” (6mm) drop for each 12” (305mm).
Wall Thickness Guidelines
24” maximum
3/4” minimum
insideoutside
FIGURE 20
1 - In areas where piping penetrates joists or interior
walls, hole must be large enough to allow clearance on
all sides of pipe through center of hole using a hanger.
2 - When furnace is installed in a residence where unit is
shut down for an extended period of time, such as a
vacation home, make provisions for draining conden
sate collection trap and lines.
Removal of the Furnace from Common Vent
In the event that an existing furnace is removed from a
venting system commonly run with separate gas ap
pliances, the venting system is likely to be too large to
properly vent the remaining attached appliances.
Wall
insulation
(if required)
WARNING
CARBON MONOXIDE POISONING HAZARD
Failure to follow the steps outlined below for each
appliance connected to the venting system being
placed into operation could result in carbon mon
oxide poisoning or death.
The following steps shall be followed for each ap
pliance connected to the venting system being
placed into operation, while all other appliances
connected to the venting system are not in
operation:
1 - Seal any unused openings in the common venting sys
tem.
2 - Inspect the venting system for proper size and horizontal
pitch. Determine that there is no blockage, restriction,
leakage, corrosion, or other deficiencies which could
cause an unsafe condition.
3 - Close all building doors and windows and all doors be
tween the space in which the appliances remaining
connected to the common venting system are located
and other spaces of the building. Turn on clothes dry
ers and any appliances not connected to the common
venting system. Turn on any exhaust fans, such as
range hoods and bathroom exhausts, so they will oper
ate at maximum speed. Do not operate a summer ex
haust fan. Close fireplace dampers.
4 - Follow the lighting instructions. Turn on the appliance
that is being inspected. Adjust the thermostat so that
the appliance operates continuously.
5 - After the main burner has operated for 5 minutes, test
for leaks of flue gases at the draft hood relief opening.
Use the flame of a match or candle.
6 - After determining that each appliance connected to the
common venting system is venting properly, (step 3)
return all doors, widows, exhaust fans, fireplace damp
ers, and any other gas-burning appliances to their pre
vious mode of operation.
7 - If a venting problem is found during any of the preced
ing tests, the common venting system must be modi
fied to correct the problem.
Page 15
Page 16
Resize the common venting system to the minimum
vent pipe size determined by using the appropriate
tables in Appendix G. (These are in the current stan
dards of the National Fuel Gas Code ANSI Z223.1.
CHIMNEY
OR GAS
VENT
(Check sizing
for water
heater only)
FURNACE
(Replaced
by EL296)
REPLACING FURNACE THAT
WAS PART OF A COMMON
VENT SYSTEM
WATER
HEATER
OPENINGS
(To Adjacent
Room)
If an EL296UHE furnace replaces a furnace which
was commonly vented with another gas appliance,
the size of the existing vent pipe for that gas ap
pliance must be checked. Without the heat of the
original furnace flue products, the existing vent pipe
is probably oversized for the single water heater or
other appliance. The vent should be checked for
proper draw with the remaining appliance.
NOTE - In Non‐Direct Vent installations, combustion air is
taken from indoors or ventilated attic or crawlspace and flue
gases are discharged outdoors. In Direct Vent installations,
combustion air is taken from outdoors and flue gases are
discharged outdoors.
Intake and exhaust pipe sizing -- Size pipe according to
tables 3 and
5. Count all elbows inside and outside the
home. Table 3 lists the minimum vent pipe lengths per
mitted. Table 5 lists the maximum pipe lengths permitted.
Regardless of the diameter of pipe used, the standard roof
and wall terminations described in section Exhaust PipingTerminations should be used. Exhaust vent termination
pipe is sized to optimize the velocity of the exhaust gas as
it exits the termination. Refer to table 8.
In some applications which permit the use of several differ
ent sizes of vent pipe, a combination vent pipe may be
used. Contact Lennox' Application Department for assis
tance in sizing vent pipe in these applications.
NOTE - The exhaust collar on all models is sized to ac
commodate 2” Schedule 40 vent pipe. In horizontal ap
plications, any transition to exhaust pipe larger than 2”
must be made in vertical runs of the pipe. Therefore a 2”
elbow must be added before the pipe is transitioned to
any size larger than 2”. This elbow must be added to the
elbow count used to determine acceptable vent lengths.
Contact the Application Department for more information
concerning sizing of vent systems which include multiple
pipe sizes.
FIGURE 21
Exhaust Piping (Figures 22, 24 and 25)
Route piping to outside of structure. Continue with installa
tion following instructions given in piping termination sec
tion.
CAUTION
Do not discharge exhaust into an existing stack or
stack that also serves another gas appliance. If verti
cal discharge through an existing unused stack is re
quired, insert PVC pipe inside the stack until the end
is even with the top or outlet end of the metal stack.
CAUTION
The exhaust vent pipe operates under positive pres
sure and must be completely sealed to prevent leak
age of combustion products into the living space.
Vent Piping Guidelines
The EL296UHE can be installed as either a Non-Direct
Vent or a Direct Vent gas central furnace.
Horizontal Installation Offset Requirements
Exhaust Pipe
Horizontal
12” Max.
Gas Furnace
NOTE - All horizontal runs of exhaust pipe must slope back to
ward unit. A minimum of 1/4” (6mm) drop for each 12” (305mm)
of horizontal run is mandatory for drainage.
NOTE - Exhaust pipe MUST be glued to furnace exhaust fittings.
NOTE - Exhaust piping should be checked carefully to make
sure there are no sags or low spots.
12” Min.
FIGURE 22
TABLE 3
MINIMUM VENT PIPE LENGTHS
EL296UHE
MODEL
045, 070, 090, 110, 135
*Any approved termination may be added to the minimum length listed.
MIN. VENT LENGTH*
15 ft. or
5 ft. plus 2 elbows or
10 ft. plus 1 elbow
Page 16
Page 17
Use the following steps to correctly size vent pipe diameter.
Piping Size Process
What is the
furnace capacity?
1
045, 070, 090,
110 or 135?
Which style termination
2
3
4
being used?
Standard or concentric?
See table 4.
Which needs
most elbows?
Intake or
exhaust?
How many elbows?
Count all elbows inside
and outside house.
IMPORTANT
Do not use screens or perforated metal in exhaust or
intake terminations. Doing so will cause freeze-ups
and may block the terminations.
Desired pipe size?
5
6
7
2”, 2-1/2”, 3”
What is the altitude of
the furnace installation?
Use table 5 or 6 to find
max intake or exhaust pipe
length. Includes all vent
pipe and elbows inside
and outside the house.
FIGURE 23
Page 17
Page 18
Vent
Input Size
Pipe
Dia. in.
51W12 (CA)
2
045
2-1/2
3
2
070
2-1/2
3
2
090
2-1/2
3
2YESYESYES
110
2-1/2YESYES
3YESYES
1353YES
OUTDOOR TERMINATION USAGE
TABLE 4
STANDARDCONCENTRIC
FlushMount
Kit
51W11 (US)
3
YESYES
3
YESYES
3
YESYES
3
YESYES
3
YESYES
3
YESYES
3
YESYESYES
3
YESYESYES
3
YESYESYES
22G44 (US)
4
30G28 (CA)
Wall KitWall Ring Kit
2 inch3 inch2 inch
44J40 (US)
4
81J20 (CA)
1
YES
1
YES
1
YES
1
YES
1
YES
1
YES
YES
15F74
1
YES
1
YES
1
YES
1
YES
1
YES
1
YES
1-1/2 inch2 inch3 inch
Field
Fabricated
5
YES
5
YES
5
YES
5
YES
5
YES
5
YES
5
YESYESYES
5
YESYESYES
5
YESYESYES
5
YESYESYES
5
YESYESYES
5
YESYESYES
5
YESYES
71M80
(US)
4
44W92
(CA)
2
YES
2
YES
2
YES
2
YES
2
YES
2
YES
69M29
(US)
4
44W92
(CA)
60L46 (US)
4
44W93 (CA)
NOTE - Standard Terminations do not include any vent pipe or elbows external to the structure. Any vent pipe or elbows external to the structure must be included in total vent length
calculations. See vent length tables.
Concentric kits 71M80 and 44W92 include 1-1/2” outdoor accelerator, when used with 045 and 070 input models.
3
Flush mount kit 51W11 and 51W12 includes 1-1/2 in. outdoor exhaust accelerator, required when used with 045, 070 and 090 input models.
4
Termination kits 30G28, 44W92, 44W93 and 81J20 are certified to ULC S636 for use in Canada only.
5
See table 8 for vent accelerator requirements.
Page 18
Page 19
Maximum Allowable Intake or Exhaust Vent Length in Feet
TABLE 5
NOTE - Size intake and exhaust pipe length separately. Values in table are for Intake OR Exhaust, not combined total. Both Intake and Exhaust must be same pipe
size.
NOTE - Additional vent pipe and elbows used to terminate the vent pipe outside the structure must be included in the total vent length calculation.
Standard Termination at Elevation 0 - 4500 ft
Number Of
90° Elbows
Used
181664424
276613919110110885313313211311 3109
3715634141051058348128127108108104
4665129
56146249595733811811 7989894
65641199090683311311 2939389
751361485856328108107888884
84631
94126757553189897787874
103621707048139392737369
045070090110135045070090110135045070090110135
2” Pipe2-1/2” Pipe3” Pipe
ModelModelModel
n/a
n/a
n/a
1151159358
100100784312312210310399
n/a
80805823103102838379
13813711811 811 4
Standard Termination Elevation 4500 - 10,000 ft
Number Of
90° Elbows
Used
1816644
2766139110110885313313211311 3109
37156341051058348128127108108104
4665129100100784312312210310399
56146249595733811811 7989894
65641199090683311311 2939389
751361485856328108107888884
84631
94126757553189897787874
103621707048139392737369
045070090110135045070090110135045070090110135
2” Pipe2-1/2” Pipe3” Pipe
ModelModelModel
n/a
n/an/a
1151159358
n/a
80805823103102838379
13813711811 811 4
See concentric terminations next page.
Page 19
Page 20
Maximum Allowable Intake or Exhaust Vent Length in Feet
TABLE 5 Continued
Size intake and exhaust pipe length separately. Values in table are for Intake OR Exhaust, not combined total. Both Intake and Exhaust must be same pipe size.
Concentric Termination at Elevation 0 - 4500 ft
Number Of
90° Elbows
Used
04507009011 0135045070090110135045070090110135
173584222
268533717100100844911611 6109109100
3634832129595794411111110410495
4584327
553382285856934101101949485
6483317808064299696898980
7432812757559249191848475
83823
93318656549148181747465
102813606044n/a7676696960
2” Pipe2-1/2” Pipe3” Pipe
ModelModelModel
1051058954
90907439106106999990
n/a
n/a
707054198686797970
n/a
12112111411 4105
n/a
Concentric Termination Elevation 4501 - 10,000 ft
Number Of
90° Elbows
Used
04507009011 0135045070090110135045070090110135
1735842
2685337100100844911611 6109109100
36348329595794411111110410495
458432790907439106106999990
553382285856934101101949485
6483317808064299696898980
7432812757559249191848475
83823
93318656549148181747465
102813606044n/a7676696960
2” Pipe2-1/2” Pipe3” Pipe
ModelModelModel
1051058954
n/an/a
707054198686797970
n/a
12112111411 4105
n/a
Page 20
Page 21
Maximum Allowable Exhaust Vent Lengths With Furnace Installed in a Closet or Basement Using Ventilated
TABLE 6
Attic or Crawl Space For Intake Air in Feet
NOTE - Size intake and exhaust pipe length separately. Values in table are for Intake OR Exhaust, not combined total. Both Intake and Exhaust must be same pipe
size.
NOTE - Additional vent pipe and elbows used to terminate the vent pipe outside the structure must be included in the total vent length calculation.
Standard Termination at Elevation 0 - 4500 ft
Number Of
90° Elbows
Used
171563414
266512999595733811 3112939389
3614624490906833108107888884
4564119
5513614808058239897787874
646319857563189392737369
741264707048138887686864
83621
9311660603837877585854
102611555533n/a7372535349
045070090110135045070090110135045070090110135
2” Pipe2-1/2” Pipe3” Pipe
ModelModelModel
n/a
n/a
n/a
1001007843
85856328103102838379
n/a
65654388382636359
118117989894
Standard Termination Elevation 4500 - 10,000 ft
Number Of
90° Elbows
Used
1715634
26651299595733811311 2939389
361462490906833108107888884
456411985856328103102838379
5513614808058239897787874
646319858553189392737369
741264707048138887686864
83621
9311660603837877585854
102611555533n/a7372535349
045070090110135045070090110135045070090110135
2” Pipe2-1/2” Pipe3” Pipe
ModelModelModel
n/a
n/an/a
1001007843
n/a
65654388382636359
118117989894
Page 21
Page 22
TYPICAL EXHAUST AND INTAKE PIPE CONNECTIONS IN UPFLOW DIRECT OR
NON-DIRECT VENT APPLICATIONS
EXHAUST
2”
INTAKE
2”
EXHAUSTINTAKE
3”
TRANSITION
*2”
2”
3”
TRANSITION
*2”
2”
DO NOT transition
from smaller to larger
pipe in horizontal runs
of exhaust pipe.
* When transitioning up in pipe size, use the shortest length of 2” PVC pipe possible.
FIGURE 24
2”
or
2”
TYPICAL EXHAUST AND INTAKE PIPE CONNECTIONS IN HORIZONTAL DIRECT OR NON-DIRECT VENT
APPLICATIONS
12” max.
EXHAUST
2”
INTAKE
EXHAUST
*2”
(RIGHT HAND DISCHARGE SHOWN)
2”
or
2”
2”
3”
*2”
2”
2”
TRANSITION
*2”
2”
or
2”
3”
*2”
45°
MAX
2”
*2”
2”
SIDE VIEW
45°
MAX
DO NOT transition
from smaller to larger
pipe in horizontal runs
of exhaust pipe.
INTAKE
* When transitioning up in pipe size, use the shortest length of 2” PVC pipe possible.
FIGURE 25
Page 22
Page 23
Intake Piping
The EL296UHE furnace may be installed in either direct
vent or non-direct vent applications. In non-direct vent
applications, when intake air will be drawn into the furnace
from the surrounding space, the indoor air quality must be
considered and guidelines listed in Combustion, Dilution
and Ventilation Air section must be followed.
Follow the next two steps when installing the unit in DirectVent applications, where combustion air is taken from
outdoors and flue gases are discharged outdoors. The
provided air intake screen must not be used in direct
vent applications (outdoors).
1 - Use transition solvent cement or a sheet metal screw
to secure the intake pipe to the inlet air connector.
2 - Route piping to outside of structure. Continue with
installation following instructions given in general
guidelines for piping terminations and intake and ex
haust piping terminations for direct vent sections. Re
fer to table
5 for pipe sizes.
TYPICAL AIR INTAKE PIPE CONNECTIONS
HORIZONTAL NON−DIRECT VENT APPLICATIONS
(Horizontal Right−Hand Air Discharge Application Shown)
PVC pipe
coupling
OR
INTAKE
DEBRIS
SCREEN
(Provided)
NOTE - Debris screen may be positioned straight out
(preferred) or with an elbow rotated to face down.
TYPICAL AIR INTAKE PIPE CONNECTIONS
UPFLOW NON−DIRECT
VENT APPLICATIONS
INTAKE
DEBRIS
SCREEN
(Provided)
NOTE - Debris screen and elbow may be rotated, so that
screen may be positioned to face forward or to either side.
FIGURE 26
FIGURE 27
Follow the next two steps when installing the unit in Non‐
Direct Vent applications where combustion air is taken
from indoors or ventilated attic or crawlspace and flue
gases are discharged outdoors.
1 - Use field-provided materials and the factory-provided
air intake screen to route the intake piping as shown in
figure 26 or 27. Maintain a minimum clearance of 3”
(76mm) around the air intake opening. The air intake
opening (with the protective screen) should always be
directed forward or to either side in the upflow position,
and either straight out or downward in the horizontal
position.
The air intake piping must not terminate too close
to the flooring or a platform. Ensure that the intake
air inlet will not be obstructed by loose insulation
or other items that may clog the debris screen.
2 - If intake air is drawn from a ventilated attic (figure 28)
or ventilated crawlspace (figure 29) the exhaust vent
length must not exceed those listed in table 6. If 3” di
ameter pipe is used, reduce to 2” diameter pipe at the
termination point to accommodate the debris screen.
3 - Use a sheet metal screw to secure the intake pipe to
the connector, if desired.
Page 23
Page 24
CAUTION
e
If this unit is being installed in an application with
combustion air coming in from a space serviced by
an exhaust fan, power exhaust fan, or other device
which may create a negative pressure in the space,
take care when sizing the inlet air opening. The in
let air opening must be sized to accommodate the
maximum volume of exhausted air as well as the
maximum volume of combustion air required for
all gas appliances serviced by this space.
(Inlet Air from Ventilated Attic and Outlet Air to Outside)
Roof T erminated
Exhaust Pipe
* See table 6 for maximum vent lengths
NOTE-The inlet and outlet air openings shall each have a free area
of at least one square inch per 4,000 Btu (645mm
hour of the total input rating of all equipment in the enclosure.
(Inlet Air from Ventilated Crawlspace and Outlet Air to Outside)
Roof T erminated
Exhaust Pipe
EQUIPMENT IN CONFINED SPACE
Ventilation Louvers
12 in.(305mm) Abov
*Intake Debris
Screen
(Provided)
Furnace
2
per 1.17kW) per
FIGURE 28
EQUIPMENT IN CONFINED SPACE
Inlet Air
(Minimum
attic floor)
General Guidelines for Vent Terminations
In Non‐Direct Vent applications, combustion air is taken
from indoors or ventilated attic or crawlspace and the flue
gases are discharged to the outdoors. The EL296UHE is
then classified as a non‐direct vent, Category IV gas fur
nace.
In Direct Vent applications, combustion air is taken from
outdoors and the flue gases are discharged to the out
doors. The EL296UHE is then classified as a direct vent,
Category IV gas furnace.
In both Non‐Direct Vent and Direct Vent applications, the
vent termination is limited by local building codes. In the
absence of local codes, refer to the current National Fuel
Gas Code ANSI Z223-1/NFPA 54 in U.S.A., and current
CSA-B149 Natural Gas and Propane Installation Codes in
Canada for details.
Position termination according to location given in figure 30
or 31. In addition, position termination so it is free from any
obstructions and 12” above the average snow accumula
tion.
At vent termination, care must be taken to maintain
protective coatings over building materials (prolonged
exposure to exhaust condensate can destroy protective
coatings). It is recommended that the exhaust outlet not be
located within 6 feet (1.8m) of a condensing unit because
the condensate can damage the painted coating.
NOTE - See table 7 for maximum allowed exhaust pipe
length without insulation in unconditioned space during
winter design temperatures below 32°F (0°C). If required
exhaust pipe should be insulated with 1/2” (13mm) Arma
flex or equivalent. In extreme cold climate areas, 3/4”
(19mm) Armaflex or equivalent may be necessary. Insula
tion on outside runs of exhaust pipe must be painted or
wrapped to protect insulation from deterioration. Exhaust
pipe insulation may not be necessary in some specific ap
plications.
Inlet Air
(Minimum
Ventilation
Louvers
(Crawl space)
Coupling or
3 in. to 2 in.
Transition
(Field Provided)
Furnace
12 in.(305mm)
Above crawl
space floor)
*Intake Debris Screen Provided)
* See table 6 for maximum vent lengths
NOTE-The inlet and outlet air openings shall each have a free area
of at least one square inch per 4,000 Btu (645mm
hour of the total input rating of all equipment in the enclosure.
2
per 1.17kW) per
FIGURE 29
IMPORTANT
Do not use screens or perforated metal in exhaust
terminations. Doing so will cause freeze-ups and
may block the terminations.
IMPORTANT
For Canadian Installations Only:
In accordance to CSA International B149 installation
codes, the minimum allowed distance between the
combustion air intake inlet and the exhaust outlet of
other appliances shall not be less than 12 inches
(305mm).
Page 24
Page 25
Maximum Allowable Exhaust Vent Pipe Length Without Insulation
TABLE 7
In Unconditioned Space For Winter Design Temperatures
Winter Design
Temperatures
1
°F (°C)
Vent Pipe
Diameter
045070090110135
Unit Input Size
2 in.20304024N/A
32 to 21
(0 to -6)
2-1/2 in.15223040N/A
3 in.1218253232
2 in12202524N/A
20 to 1
(-7 to -17)
2-1/2 in.10142024N/A
3 in.610152020
2 in.8121822N/A
0 to -20
(-18 to -29)
2-1/2 in.681216N/A
3 in.26101212
1Refer to 99% Minimum Design Temperature table provided in the current edition of the ASHRAE Fundamentals Handbook.
NOTE - Maximum uninsulated vent lengths listed may include the termination(vent pipe exterior to the structure) and cannot exceed 5 linear feet or the
maximum allowable intake or exhaust vent length listed in table 5 or 6 which ever is less.
Page 25
Page 26
VENT TERMINATION CLEARANCES
FOR NON-DIRECT VENT INSTALLATIONS IN THE US AND CANADA
INSIDE CORNER
DETAIL
G
D
A
E
B
L
C
Fixed
F
Closed
Operable
B
Operable
B
B
VENT TERMINAL
AIR SUPPLY INLET
US Installations
A =
Clearance above grade, veranda,
porch, deck or balcony
B =
Clearance to window or
door that may be opened
C =
Clearance to permanently
closed window
D =
Vertical clearance to ventilated soffit
located above the terminal within a
12 inches (305mm) or 12 in. (305mm)
above average snow accumulation.
4 feet (1.2 m) below or to side of opening;
1 foot (30cm) above opening
* 12”
* Equal to or greater than soffit depth.
horizontal distance of 2 feet (610 mm)
from the center line of the terminal
E =
F =
G =
H =
Clearance to unventilated soffit
Clearance to outside corner
Clearance to inside corner
Clearance to each side of center line ex
tended above meter / regulator assembly
I =
Clearance to service regulator
vent outlet
J =
Clearance to non-mechanical air
supply inlet to building or the com
bustion air inlet to any other ap
* Equal to or greater than soffit depth.
* No minimum to outside corner* No minimum to outside corner
**
3 feet (.9m) within a height 15 feet (4.5m)
*
above the meter / regulator assembly
* 3 feet (.9m)
4 feet (1.2 m) below or to side of opening;
1 foot (30 cm) above opening
pliance
K =
L =
Clearance to mechanical air sup
ply inlet
Clearance above paved sidewalk or
3 feet (.9m) above if within 10 feet
(3m) horizontally
7 feet (2.1m)†
paved driveway located on public property
Clearance under veranda, porch, deck or balcony
M =
1
In accordance with the current ANSI Z223.1/NFPA 54 Natural Fuel Gas Code
2
In accordance with the current CSA B149.1, Natural Gas and Propane Installation Code
† A vent shall not terminate directly above a sidewalk or paved driveway that is
located between two single family dwellings and serves both dwellings.
‡ Permitted only if veranda, porch, deck or balcony is fully open
on a minimum of two sides beneath the floor. Lennox recommends
avoiding this location if possible.
*12 inches (305mm)‡
FIGURE 30
H
B
Fixed
Closed
A
J
I
M
AREA WHERE TERMINAL
IS NOT PERMITTED
1
Canadian Installations
12 inches (305mm) or 12 in. (305mm)
above average snow accumulation.
6 inches (152mm) for appliances <10,000
Btuh (3kw), 12 inches (305mm) for
appliances > 10,000 Btuh (3kw) and
<100,000 Btuh (30kw), 36 inches (.9m)
for appliances > 100,000 Btuh (30kw)
* 12”
* Equal to or greater than soffit depth.
* Equal to or greater than soffit depth.
3 feet (.9m) within a height 15 feet (4.5m)
above the meter / regulator assembly
3 feet (.9m)
6 inches (152mm) for appliances <10,000
Btuh (3kw), 12 inches (305mm) for
appliances > 10,000 Btuh (3kw) and
<100,000 Btuh (30kw), 36 inches (.9m)
for appliances > 100,000 Btuh (30kw)
6 feet (1.8m)
7 feet (2.1m)†
12 inches (305mm)‡
*For clearances not specified in ANSI Z223.1/NFPA 54 or CSA
B149.1, clearance will be in accordance with local installation
codes and the requirements of the gas supplier and these instal
lation instructions.”
K
2
Page 26
Page 27
VENT TERMINATION CLEARANCES
FOR DIRECT VENT INSTALLATIONS IN THE US AND CANADA
INSIDE CORNER
DETAIL
G
D
A
E
B
L
C
Fixed
F
Closed
Operable
B
Operable
B
B
VENT TERMINAL
AIR SUPPLY INLET
US Installations
A =
B =
Clearance above grade, veranda,
porch, deck or balcony
Clearance to window or
door that may be opened
12 inches (305mm) or 12 in. (305mm)
above average snow accumulation.
6 inches (152mm) for appliances <10,000
Btuh (3kw), 9 inches (228mm) for ap
pliances > 10,000 Btuh (3kw) and <50,000
Btuh (15 kw), 12 inches (305mm) for ap
pliances > 50,000 Btuh (15kw)
C =
Clearance to permanently
closed window
Vertical clearance to ventilated soffit
D =
located above the terminal within a
* Equal to or greater than soffit depth
horizontal distance of 2 feet (610mm)
from the center line of the terminal
E =
F =
G =
H =
Clearance to unventilated soffit
Clearance to outside corner
Clearance to inside corner
Clearance to each side of center line ex
tended above meter / regulator assembly
I =
Clearance to service regulator
vent outlet
J =
Clearance to non-mechanical air
supply inlet to building or the com
bustion air inlet to any other ap
pliance
* Equal to or greater than soffit depth* Equal to or greater than soffit depth
* No minimum to outside corner
*
3 feet (.9m) within a height 15 feet (4.5m)
above the meter / regulator assembly
3 feet (.9m)
*
6 inches (152mm) for appliances <10,000
Btuh (3kw), 9 inches (228mm) for ap
pliances > 10,000 Btuh (3kw) and <50,000
Btuh (15 kw), 12 inches (305mm) for ap
pliances > 50,000 Btuh (15kw)
K =
Clearance to mechanical air sup
ply inlet
L =
Clearance above paved sidewalk or
paved driveway located on public property
Clearance under veranda, porch, deck or balcony
M =
1
In accordance with the current ANSI Z223.1/NFPA 54 Natural Fuel Gas Code
2
In accordance with the current CSA B149.1, Natural Gas and Propane Installation Code
† A vent shall not terminate directly above a sidewalk or paved driveway that is located
between two single family dwellings and serves both dwellings.
‡ Permitted only if veranda, porch, deck or balcony is fully open on a minimum of
two sides beneath the floor. Lennox recommends avoiding this location if possible.
3 feet (.9m) above if within 10 feet
(3m) horizontally
* 7 feet (2.1m)
*12 inches (305mm)‡
FIGURE 31
A
* 12”
H
Fixed
Closed
J
B
I
M
K
AREA WHERE TERMINAL
IS NOT PERMITTED
1
Canadian Installations
2
12 inches (305mm) or 12 in. (305mm)
above average snow accumulation.
6 inches (152mm) for appliances <10,000
Btuh (3kw), 12 inches (305mm) for
appliances > 10,000 Btuh (3kw) and
<100,000 Btuh (30kw), 36 inches (.9m)
for appliances > 100,000 Btuh (30kw)
* 12”
* Equal to or greater than soffit depth* Equal to or greater than soffit depth
* No minimum to outside corner
*
3 feet (.9m) within a height 15 feet (4.5m)
above the meter / regulator assembly
3 feet (.9m)
6 inches (152mm) for appliances <10,000
Btuh (3kw), 12 inches (305mm) for
appliances > 10,000 Btuh (3kw) and
<100,000 Btuh (30kw), 36 inches (.9m)
for appliances > 100,000 Btuh (30kw)
6 feet (1.8m)
7 feet (2.1m)†
12 inches (305mm)‡
*For clearances not specified in ANSI Z223.1/NFPA 54 or CSA
B149.1, clearance will be in accordance with local installation
codes and the requirements of the gas supplier and these
installation instructions.”
Page 27
Page 28
Details of Intake and Exhaust Piping Terminations for
Direct Vent Installations
NOTE - In Direct Vent installations, combustion air is tak
en from outdoors and flue gases are discharged to out
doors.
NOTE - Flue gas may be slightly acidic and may adversely
affect some building materials. If any vent termination is
used and the flue gasses may impinge on the building ma
terial, a corrosion-resistant shield (minimum 24 inches
square) should be used to protect the wall surface. If the
optional tee is used, the protective shield is recommended.
The shield should be constructed using wood, plastic,
sheet metal or other suitable material. All seams, joints,
cracks, etc. in the affected area should be sealed using an
appropriate sealant. See figure 35.
Intake and exhaust pipes may be routed either horizontally
through an outside wall or vertically through the roof. In at
tic or closet installations, vertical termination through the
roof is preferred. Figures 32 through 46 show typical
terminations.
1 - Intake and exhaust terminations are not required to be
in the same pressure zone. You may exit the intake on
one side of the structure and the exhaust on another
side (figure 33). You may exit the exhaust out the roof
and the intake out the side of the structure (figure 34).
2 - Intake and exhaust pipes should be placed as close
together as possible at termination end (refer to il
lustrations). Maximum separation is 3” (76MM) on roof
terminations and 6” (152MM) on side wall termina
tions.
NOTE - When venting in different pressure zones, the
maximum separation requirement of intake and ex
haust pipe DOES NOT apply.
3 - On roof terminations, the intake piping should termi
nate straight down using two 90° elbows (See figure
32).
4 - Exhaust piping must terminate straight out or up as
shown. A reducer may be required on the exhaust pip
ing at the point where it exits the structure to improve
the velocity of exhaust away from the intake piping.
See table 8.
NOTE - Care must be taken to avoid recirculation of ex
haust back into intake pipe.
5 - On field-supplied terminations for side wall exit, ex
haust piping may extend a maximum of 12 inches
(305MM) for 2” PVC and 20 inches (508MM) for 3”
(76MM) PVC beyond the outside wall. Intake piping
should be as short as possible. See figures 36 and 37.
6 - On field-supplied terminations, a minimum distance
between the end of the exhaust pipe and the end of
the intake pipe without a termination elbow is 8” and a
minimum distance of 6” with a termination elbow. See
figures 36 and 37.
Inches(MM)
8” (203MM) MIN
12” (305MM) ABOVE
AVERAGE SNOW
ACCUMULATION
3” (76MM) OR
2” (51MM) PVC
PROVIDE SUPPORT
FOR INTAKE AND
EXHAUST LINES
DIRECT VENT ROOF TERMINATION KIT
3”(76MM) MAX.
(15F75 or 44J41)
SIZE TERMINATION
PIPE PER TABLE 8.
UNCONDITIONED
ATTIC SPACE
1/2” (13MM) FOAM
INSULATION IN
UNCONDITIONED
SPACE
FIGURE 32
Exiting Exhaust and Intake Vent
(different pressure zones)
Exhaust
Pipe
Furnace
Inlet Air
(Minimum 12 in.
305 MM) above
grade or snow
accumulation
FIGURE 33
Exiting Exhaust and Intake Vent
(different pressure zones)
Roof T
erminated
Exhaust Pipe
Inlet Air
Furnace
(Minimum 12 in.
305 MM) above
grade or snow
accumulation
FIGURE 34
TABLE 8
EXHAUST PIPE TERMINATION SIZE REDUCTION
EL296UHE
MODEL
*045 and 070
*0902” (51MM)
1102” (51MM)
1352” (51MM)
*EL296UHE-045, -070 and -090 units with the flush mount termination must
use the 1-1/2”accelerator supplied with the kit.
Termination
Pipe Size
1-1/2” (38MM)
Page 28
Page 29
7 - If intake and exhaust piping must be run up a side wall
to position above snow accumulation or other ob
structions, piping must be supported every 24”
(610MM) as shown in figures 36 and 37. In addition,
close coupled wall termination kits must be extended
for use in this application. See figures 44 and 45.
When exhaust and intake piping must be run up an
outside wall, the exhaust piping must be terminated
with pipe sized per table 8.The intake piping may be
equipped with a 90° elbow turndown. Using turndown
will add 5 feet (1.5m) to the equivalent length of the
pipe.
Alternate Terminations
(Tee & Forty-Five Degree Elbows Only)
8 - A multiple furnace installation may use a group of up to
four terminations assembled together horizontally, as
shown in figure 41.
B
D
Intake
C
2
A
1
B
C
A
Exhaust
D
3
Front View of
Intake and Exhaust
Intake
Exhaust
TABLE 9
D
E
1
B
12”
C
2
A
A- Clearance above
grade or average snow
accumulation
B-Horizontal
separation between
intake and exhaust
C-Minimum from
end of exhaust to
inlet of intake
D-Exhaust pipe length
E-Wall support distance
from top of each pipe
(intake/exhaust)
2” (51MM)
Vent Pipe
12” (305MM) Min.
6” (152MM) Min.
24” (610MM) Max
9” (227MM) Min.
12” (305MM) Min.
16” (405MM) Max.
6” (152MM) Max.
3” (76MM)
Vent Pipe
12” (305MM) Min.
6” (152MM) Min.
24” (610MM) Max
9” (227MM) Min.
12” (305MM) Min.
20” (508MM) Max.
6” (152MM) Max.
1
The exhaust termination tee should be connected to the 2” or 3” PVC flue pipe as shown in the illustration. Do
not use an accelerator in applications that include an exhaust termination tee. The accelerator is not required.
2
As required. Flue gas may be acidic and may adversely affect some building materials. If a side wall vent
termination is used and flue gases will impinge on the building materials, a corrosion-resistant shield (24 inches
square) should be used to protect the wall surface. If optional tee is used, the protective shield is recommende
d. The shield should be constructed using wood, sheet metal or other suitable material. All seams, joints,
cracks, etc. in affected area, should be sealed using an appropriate sealant.
3
Exhaust pipe 45° elbow can be rotated to the side away from the combustion air inlet to direct exhaust away
from adjacent property. The exhaust must never be directed toward the combustion air inlet.
FIGURE 35
Page 29
Page 30
FIELD FABRICATED WALL TERMINATION OR
(15F74) WALL RING TERMINATION KIT
FIELD FABRICATED WALL TERMINATION OR
(15F74) WALL RING TERMINATION KIT
With INTAKE ELBOW
NOTE - FIELD-PROVIDED
REDUCER MAY BE
REQUIRED TO ADAPT
LARGER VENT PIPE SIZE
TO TERMINATION
C
* WALL
SUPPORT
C
1/2” (13MM) ARMAFLEX
INSULATION IN UN
CONDITIONED SPACE
SIZE TERMINATION
PER TABLE 8
D
B
A
1/2” (13MM) ARMAFLEX INSULATION
IN UNCONDITIONED SPACE
E
STRAIGHT
APPPLICATION
D
B
A
EXTENDED
APPLICATION
NOTE - FIELD-PROVIDED
REDUCER MAY BE
REQUIRED TO ADAPT
LARGER VENT PIPE SIZE
TO TERMINATION
C
* WALL
SUPPORT
C
1/2” (13MM) ARMAFLEX
INSULATION IN UN
CONDITIONED SPACE
SIZE TERMINATION
PER TABLE 8
D
B
A
1/2” (13MM) ARMAFLEX INSULATION
IN UNCONDITIONED SPACE
E
STRAIGHT
APPPLICATION
D
B
A
EXTENDED
APPLICATION
See venting table 5 for maximum venting lengths with this
arrangement.
* Use wall support every 24” (610MM). Use two wall supports if
extension is greater than 24” (610MM) but less than 48” (1219 MM).
NOTE - One wall support must be 6” (152MM) from top of each pipe
(intake and exhaust)
A-Minimum clearance
above grade or average
snow accumulation
B-Maximum horizontal
separation between
intake and exhaust
C-Minimum from
end of exhaust to
inlet of intake
D-Maximum exhaust
pipe length
E-Maximum wall support
distance from top of each
pipe (intake/exhaust)
2” (51MM)
Vent Pipe
12” (305MM)
6” (152MM)6” (152MM)
8” (203MM)8” (203MM)
12” (305MM)20” (508MM)
6” (152MM)6” (152MM)
3” (7MM)
Vent Pipe
12” (305MM)
FIGURE 36
See venting table 5 for maximum venting lengths with this
arrangement.
* Use wall support every 24” (610MM). Use two wall supports if
extension is greater than 24” (610MM) but less than 48” (1219 MM).
NOTE - One wall support must be 6” (152MM) from top of each pipe
(intake and exhaust)
A-Minimum clearance
above grade or average
snow accumulation
B-Maximum horizontal
separation between
intake and exhaust
C-Minimum from
end of exhaust to
inlet of intake
D-Maximum exhaust
pipe length
E-Maximum wall support
distance from top of each
pipe (intake/exhaust)
2” (51MM)
Vent Pipe
12” (305MM)
6” (152MM)6” (152MM)
6” (152MM)
12” (305MM)20” (508MM)
6” (152MM)6” (152MM)
3” (76MM)
Vent Pipe
12” (305MM)
6” (152MM)
FIGURE 37
Page 30
Page 31
2” EXTENSION FOR 2” PVC
PIPE1” EXTENSION FOR 3”
PVC PIPE
FURNACE
4''
EXHAUST
PIPE
FURNACE
INTAKE
PIPE
GLUE EXHAUST
END FLUSH INTO
TERMINATION
FLAT
SIDE
1-1/2” ACCELERATOR
(all -45, -070 and -090 units)
FLUSH-MOUNT SIDE WALL TERMINATION
51W11 (US) or 51W12 (Canada)
FIGURE 38
1 1/2” (38mm) accelerator
EXHAUST
12” (305mm)
Minimum
Above Average
Snow
Accumulation
VENT
provided on 71M80 & 44W92
kits for EL296UH045E36B, &
070E36B
INTAKE
AIR
FLASHING
(Not Furnished)
SHEET METAL STRAP
(Clamp and sheet metal strap
must be field installed to support
the weight of the termination kit.)
CLAMP
FIELD-PROVIDED
REDUCER MAY BE REQUIRED
TO ADAPT LARGER VENT
PIPE SIZE TO TERMINATION
DIRECT VENT CONCENTRIC ROOFTOP TERMINATION
71M80, 69M29 or 60L46 (US)
44W92 or 44W93 (Canada)
FIGURE 39
FIELD-PROVIDED
REDUCER MAY BE REQUIRED
TO ADAPT LARGER VENT
PIPE SIZE TO TERMINATION
OUTSIDE
WALL
EXHAUST
VENT
INTAKE
AIR
CLAMP
(Not Furnished)
DIRECT VENT CONCENTRIC WALL TERMINATION
71M80, 69M29 or 60L46 (US)
44W92 or 44W93 (Canada)
1-1/2” (38mm) accelerator
provided on 71M80 & 44W92
kits for EL296UH045E36B, &
INTAKE
INTAKE
AIR
AIR
070E36B
12” (305mm) Min.
above grade or
average snow
accumulation.
GRADE
FIGURE 40
EXHAUST
VENT
EXHAUST
VENT
5”
(127MM)
5-1/2”
(140mm)
12”
(305MM)
INTAKE
AIR
18” MAX.
(457MM)
Front View
EXHAUST VENT
12” (305MM) Min.
above grade or
Inches (MM)
INTAKE
average snow
accumulation.
AIR
optional intake elbow
Side View
OPTIONAL VENT TERMINATION FOR MULTIPLE UNIT
INSTALLATION OF DIRECT VENT WALL TERMINATION KIT
(22G44, 44J40, 30G28 or 81J20)
FIGURE 41
Front View
INTAKE
AIR
EXHAUST VENT
SIZE
TERMINATION
PIPE PER
TABLE 8.
Top View
1/2” (13MM) Foam Insulation
in Unconditioned Space
FIELD-
PROVIDED
REDUCER MAY
BE REQUIRED
TO ADAPT
LARGER VENT
PIPE SIZE TO
TERMINATION
EXHAUST VENT
INTAKE AIR
6 (152MM) MIN.
OUTSIDE WALL
DIRECT VENT WALL TERMINATION KIT
(30G28 or 81J20)
FIGURE 42
Front View
INTAKE
AIR
1/2” (13MM) Foam Insulation
in Unconditioned Space
FIELD-
PROVIDED
REDUCER MAY
BE REQUIRED
TO ADAPT
LARGER VENT
PIPE SIZE TO
TERMINATION
DIRECT VENT WALL TERMINATION KIT
(22G44 or 44J40)
EXHAUST VENT
SIZE
TERMINATION
PIPE PER
TABLE 8.
Top View
EXHAUST VENT
INTAKE AIR
8” (206MM) MIN.
OUTSIDE WALL
FIGURE 43
Page 31
Page 32
WALL TERMINATION KITS (CLOSE−COUPLE)
EXTENDED VENT FOR GRADE CLEARANCE
If intake and exhaust pipe is less than 12 in. (305 MM)
above snow accumulation or other obstructions, field−
fabricated piping must be installed.
8” (203mm) Min. for 2” (51MM) & 3” (76MM) DIA. pipe
WALL SUPPORT*
6” (152 MM)
Maximum
INTAKE
AIR
between the end of the exhaust pipe and intake pipe
12” (305MM) Max. for 2” (51MM) Dia. Exhaust
20” (508MM) Max. for 3” (76MM) Dia. Exhaust
8” (203 mm) Min.
12” (305 MM) Max. for 2” (51MM) Dia. Exhaust
20” (508MM) Max. for 3” (76MM) Dia. Exhaust
2 inch (51 mm) 22G44 (US)
3 inch (76 mm) 44J40 (US)
EXHAUST
AIR
INTAKE
AIR
5” (127 mm)
12” (305 MM) Minimum
Above Grade or Average
Snow Accumulation
GRADE
*Use wall support every 24” (610). Use two supports if
extension is greater than 24” but less than 48”.
REDUCER MAY BE REQUIRED TO ADAPT
LARGER VENT PIPE SIZE TO TERMINATION
FIELD-PROVIDED
12”
(305 mm)
1/2” (13 mm)
FOAM INSULATION
(Field−Furnished)
EXHAUST
AIR
12” (305MM) Minimum
5−1/2”
(140 mm)
Above Grade or Average
Snow Accumulation
GRADE
WALL TERMINATION KITS (CLOSE−COUPLE)
EXTENDED VENT FOR GRADE CLEARANCE
2 inch (51 mm) 30G28 (WTK Canada)
3 inch (76 mm) 81J20 (WTK Canada)
See Installation Instructions for additional information.
If intake and exhaust pipe is less than 12 in. (305 MM)
above snow accumulation or other obstructions, field−
fabricated piping must be installed.
WALL SUPPORT*
6” (152 MM)
Maximum
INTAKE
AIR
12” (305 MM) Max. for 2” (51 MM) Dia. Exhaust
20” (508 MM) Max. for 3” (76 MM) Dia. Exhaust
6” (152 MM)
Minimum
6” (152 MM)
Minimum
FIGURE 44
EXHAUST
AIR
12” (305 MM) Minimum
Above Grade or Average
Snow Accumulation
GRADE
REDUCER MAY BE REQUIRED TO ADAPT
LARGER VENT PIPE SIZE TO TERMINATION
FIELD-PROVIDED
12”
(305 mm)
INTAKE
AIR
5” (127 mm)
5−1/2”
(140 mm)
1/2” (13 mm)
FOAM INSULATION
(Field−Furnished)
EXHAUST
AIR
12” (305 MM) Minimum
Above Grade or Average
Snow Accumulation
GRADE
12” (305 MM) Max. for 2” (51 MM) Dia. Exhaust
20” (508 MM) Max. for 3” (76 MM) Dia. Exhaust
FIGURE 45
Page 32
*Use wall support every 24” (610). Use two supports if
extension is greater than 24” but less than 48”.
Page 33
EL296UHE DIRECT VENT APPLICATION
USING EXISTING CHIMNEY
STRAIGHT-CUT OR
3”-8”
(76MM-203MM)
8” - 12”
(203MM - 305MM)
Minimum 12” (305MM)
above chimney top
plate or average snow
accumulation
*SIZE TERMINATION
PIPE PER TABLE 8.
NOTE - Do not discharge exhaust gases directly into any chimney or vent stack. If ver
tical discharge through an existing unused chimney or stack is required, insert piping
inside chimney until the pipe open end is above top of chimney and terminate as illus
trated. In any exterior portion of chimney, the exhaust vent must be insulated.
INTAKE PIPE
INSULATION (optional)
SHEET
METAL TOP
PLATE
INSULATE
TO FORM
SEAL
ANGLE-CUT IN DIRECTION
OF ROOF SLOPE *
EXHAUST VENT
1/2” (13MM)
WEATHERPROOF
INSULATION
SHOULDER OF FITTINGS
PROVIDE SUPPORT
OF PIPE ON TOP PLATE
3” - 8”
(76MM-
203MM)
ALTERNATE
INTAKE PIPE
EXTERIOR
PORTION OF
CHIMNEY
FIGURE 46
Details of Exhaust Piping Terminations for Non‐Direct
Vent Applications
Exhaust pipes may be routed either horizontally through an
outside wall or vertically through the roof. In attic or closet
installations, vertical termination through the roof is pre
ferred. Figures 47 through 50 show typical terminations.
1 - Exhaust piping must terminate straight out or up as
shown. The termination pipe must be sized as listed in
table 8.The specified pipe size ensures proper veloc
ity required to move the exhaust gases away from the
building.
2 - On field supplied terminations for side wall exit, ex
haust piping may extend a maximum of 12 inches
(305MM) for 2” PVC and 20 inches (508MM) for 3”
(76MM) PVC beyond the outside wall. See figure 48.
SIZE TERMINATION
12” (305MM)
ABOVE AVE.
SNOW
ACCUMULATION
1/2” (13MM) FOAM
INSULATION
PIPE PER TABLE 8.
12” (305MM) MAX. for 2” (51MM)
1/2” (13MM) ARMAFLEX
INSULATION IN
UNCONDITIONED SPACE
FIELD-PROVIDED
REDUCER MAY
BE REQUIRED TO
ADAPT LARGER
VENT PIPE SIZE
TO TERMINATION
SIZE TERMINATION
PIPE PER TABLE 8.
20” (508MM) MAX. for 3” (76MM)
1/2” (13MM)
ARMAFLEX
INSULATION
PVC REDUCER
12” MIN.
(305MM)
Above Grade or
average snow
accumulation
NON-DIRECT VENT FIELD SUPPLIED WALL TERMINATION OR
(15F74) WALL TERMINATION KIT
FIGURE 48
3 - If exhaust piping must be run up a side wall to position
above snow accumulation or other obstructions, pip
ing must be supported every 24 inches (610MM) as
shown in figure 49. When exhaust piping must be run
up an outside wall, any reduction in exhaust pipe size
must be done after the final elbow.
12” (305MM) MAX. for 2” (51MM)
UNCONDITIONED
SPACE
*WALL SUPPORT
FIELD-PROVIDED
REDUCER MAY BE
REQUIRED TO
ADAPT LARGER
VENT PIPE SIZE TO
TERMINATION
1/2” (13MM) FOAM
INSULATION IN
UNCONDITIONED
SPACE
6” (152MM)
Max
OUTSIDE WALL
20” (508MM) MAX. for 3” (76MM)
SIZE TER
MINATION
PIPE PER
TABLE 8.
12” (305MM)
ABOVE GRADE OR
AVERAGE SNOW
ACCUMULATION
1/2” (13MM) FOAM
INSULATION
NON-DIRECT VENT FIELD SUPPLIED WALL TERMINATION
EXTENDED OR (15F74) WALL TERMINATION VENT PIPE
*Use wall support every 24” (610). Use two supports if extension is
greater than 24” but less than 48”.
EXTENDED
FIGURE 49
3” (76MM) OR
2” (51MM) PVC
PROVIDE SUPPORT
FOR EXHAUST LINES
UNCONDITIONED
NON-DIRECT VENT ROOF TERMINATION KIT
(15F75 or 44J41)
FIGURE 47
ATTIC SPACE
Page 33
Page 34
EL296UHE NON-DIRECT VENT APPLICATION
USING EXISTING CHIMNEY
SIZE TERMINATION
PIPE PER TABLE 8.
Minimum 12” (305MM)
above chimney top
plate or average snow
accumulation
SHEET
METAL TOP
PLATE
STRAIGHT-CUT OR
ANGLE-CUT IN DIRECTION
OF ROOF SLOPE
EXHAUST VENT
1/2” (13MM)
WEATHERPROOF
INSULATION
SHOULDER OF FITTINGS
PROVIDE SUPPORT
OF PIPE ON TOP PLATE
CONDENSATE TRAP AND PLUG LOCATIONS
(Unit shown in upflow position)
Trap
(same on
right side)
1-1/2 in.
Plug
(same on left side)
INSULATE
TO FORM
SEAL
NOTE - Do not discharge exhaust gases directly into any chimney or vent stack. If ver
tical discharge through an existing unused chimney or stack is required, insert piping
inside chimney until the pipe open end is above top of chimney and terminate as illus
trated. In any exterior portion of chimney, the exhaust vent must be insulated.
EXTERIOR
PORTION OF
CHIMNEY
FIGURE 50
Condensate Piping
This unit is designed for either right‐ or left‐side exit of con
densate piping in upflow applications. In horizontal applica
tions, the condensate trap must extend below the unit. An
8” service clearance is required for the condensate trap.
Refer to figures 51 and 53 for condensate trap locations.
Figure 59 shows trap assembly using 1/2” PVC or 3/4”
PVC.
NOTE - If necessary the condensate trap may be installed
up to 5’ away from the furnace. Use PVC pipe to connect
trap to furnace condensate outlet. Piping from furnace
must slope down a minimum of 1/4” per ft. toward trap.
1 - Determine which side condensate piping will exit the
unit, location of trap, field-provided fittings and length of
PVC pipe required to reach available drain.
2 - Use a large flat head screw driver or a 1/2” drive socket
extension and remove plug (figure 51) from the cold
end header box at the appropriate location on the side
of the unit. Install provided 3/4 NPT street elbow fitting
into cold end header box. Use Teflon tape or appropri
ate pipe dope.
3 - Install the cap over the clean out opening at the base
of the trap. Secure with clamp. See figure 59.
4 - Install drain trap using appropriate PVC fittings, glue
all joints. Glue the provided drain trap as shown in fig
ure 59. Route the condensate line to an open drain.
Condensate line must maintain a 1/4” downward slope
from the furnace to the drain.
NOTE - In upflow applications where side return
air filter is installed on same side as the conden
sate trap, filter rack must be installed beyond
condensate trap or trap must be re-located to
avoid interference.
FIGURE 51
5 - Figures 54 and 56 show the furnace and evaporator
coil using a separate drain. If necessary the conden
sate line from the furnace and evaporator coil can
drain together. See figures 55, 57 and 58.
Upflow furnace (figure 57) - In upflow furnace applica
tions the field provided vent must be a minimum 1” to a
maximum 2” length above the condensate drain outlet
connection. Any length above 2” may result in a
flooded heat exchanger if the combined primary drain
line were to become restricted.
Horizontal furnace (figure 58) - In horizontal furnace
applications the field provided vent must be a mini
mum 4” to a maximum 5” length above the condensate
drain outlet connection. Any length above 5” may re
sult in a flooded heat exchanger if the combined pri
mary drain line were to become restricted.
NOTE - In horizontal applications it is recommended to
install a secondary drain pan underneath the unit and
trap assembly.
NOTE - Appropriately sized tubing and barbed fitting
may be used for condensate drain. Attach to the drain
on the trap using a hose clamp. See figure 52.
Page 34
Page 35
Field Provided Drain Components
Elbow
Barbed Fitting
Tubing
Hose Clamp
FIGURE 52
CAUTION
Donot use copper tubing or existing copper conden
sate lines for drain line.
6 - If unit will be started immediately upon completion of
installation, prime trap per procedure outlined in Unit
Start-Up section.
Condensate line must slope downward away from the
trap to drain. If drain level is above condensate trap,
condensate pump must be used. Condensate drain
line should be routed within the conditioned space to
avoid freezing of condensate and blockage of drain
line. If this is not possible, a heat cable kit may be used
on the condensate trap and line. Heating cable kit is
available from Lennox in various lengths; 6 ft. (1.8m) kit no. 26K68; 24 ft. (7.3m) - kit no. 26K69; and 50 ft.
(15.2m) - kit no. 26K70.
EL296UHE With Evaporator
Coil Using A Separate Drain
Field Provided Vent
(1” min. 2” max. above
condensate connection)
Condensate
Drain
Connection
Evaporator drain
line required
FIGURE 54
CONDENSATE TRAP LOCATIONS
(Unit shown in upflow position with remote trap)
FieldProvidedVent
Min.1” AboveCondensate
Drain
Connection
1”
Min.
2”Max.
*5’ max.
PVCPipeOnly
Trap can be installed a
maximum 5' from furnace
To Drain
*Piping from furnace must slope down a minimum of
1/4” per ft. toward trap.
FIGURE 53
Condensate Trap With Optional Overflow Switch
From Evaporator Coil
Horizontal Furnace4”Min.to 5”Max.above
condensate drainconnection)
FurnaceCondensate
DrainConnection
Optional
FIGURE 55
Page 35
Page 36
EL296UHE with Evaporator Coil Using a Separate Drain
(Unit shown in horizontal left-hand discharge position)
Pan
Drain
Piping from furnace and evaporator coil must slope down a minimum 1/4” per ft. toward trap
EL296UHE with Evaporator
Coil Using a Common Drain
(1”min. to 2”Max.above
condensate drain connection)
Condensate
Drain
Connection
Evaporator
Coil
Condensate
DrainConnection
Evaporator drain
line required
Field Provided Vent
(4” min. to 5” max. above
condensate connection)
4”min
5”max
5’ max.
PVC Pipe Only
.
FIGURE 56
IMPORTANT
When combining the furnace and evaporator
coil drains together, the A/C condensate drain
outlet must be vented to relieve pressure in or
der for the furnace pressure switch to operate
properly.
Drain
Pan
FIGURE 57
EL296UHE with Evaporator Coil Using a Common Drain
(Unit shown in horizontal left−hand discharge position)
Evaporator
Coil
4”min
5”max
5’ max.
PVC Pipe Only
CondensateDrain
Connection
Piping from furnace and evaporator coil must slope down a minimum 1/4” per ft. toward trap
(4”min. to 5”Max.above
condensate drain connection)
FIGURE 58
Page 36
Page 37
TRAP / DRAIN ASSEMBLY USING 1/2” PVC OR 3/4” PVC
Optional Condensate Drain Connection
Adapter 3/4 inch slip X
3/4 inch mpt (not furnished)
90° Street Elbow
3/4 inch PVC
(not furnished)
Condensate Drain
Connection In Unit
90° Street Elbow
3/4 inch PVC
( furnished)
To
Trap
OptionalDrainPipingFromTrap
Drain Assembly for 1/2 inch Drain Pipe
1/2 inch PVC Pipe
(Not Furnished)
90° Elbow
1/2 inch PVC
(Not Furnished)
To
Drain
Drain Assembly for 3/4 inch Drain Pipe
1 (25 mm) Min.
2 (50 mm) Max.
Above Top Of
Condensate Drain
Connection In Unit
Elbow 3/4 inch PVC
90°
(Not Furnished)
1/2 inch PVC Pipe
(Not Furnished)
Adapter 3/4 inch slip X
3/4 inch mpt (not furnished)
V
ent
5 Feet
Maximum
3/4 inch PVC Pipe
(Not Furnished)
Coupling 3/4 inch slip X slip
(Not Furnished)
Drain Trap
Assembly
(Furnished)
Condensate Drain
Connection In Unit
90° Elbow
3/4 inch PVC
(Not Furnished)
To
Drain
DrainTrapAssembly
(Furnished)
7
(178)
Drain Trap
Clean Out
90° Elbow
3/4 inch PVC
(Not Furnished)
T
o
Coupling 3/4 inch slip X slip
Drain
DrainTrap Assembly with 1/2 inch Piping
1 (25 mm) Min. 2 (50 mm) Max. Above Top
Of Condensate Drain Connection In Unit
(Not Furnished)
Vent
1/2 inch
Condensate Drain
Connection In Unit
To
Drain
DrainTrap Assembly with 3/4 inch Piping
1 (25 mm) Min. 2 (50 mm) Max. Above Top
Of Condensate Drain Connection In Unit
Vent
3/4 inch
Condensate Drain
Connection In Unit
To
Drain
FIGURE 59
Page 37
Page 38
Gas Piping
Gas supply piping should not allow more than 0.5”W.C. drop
in pressure between gas meter and unit. Supply gas pipe
must not be smaller than unit gas connection.
CAUTION
If a flexible gas connector is required or allowed by
the authority that has jurisdiction, black iron pipe
shall be installed at the gas valve and extend outside
the furnace cabinet. The flexible connector can then
be added between the black iron pipe and the gas
supply line.
WARNING
Do not exceed 600 in-lbs (50 ft-lbs) torque when at
taching the gas piping to the gas valve.
1 - Gas piping may be routed into the unit through either
the left‐ or right‐hand side. Supply piping enters into
the gas valve from the side of the valve as shown in
figure 61.
2 - When connecting gas supply, factors such as length of
run, number of fittings and furnace rating must be con
sidered to avoid excessive pressure drop. Table 10
lists recommended pipe sizes for typical applications.
NOTE - Use two wrenches when connecting gas pip
ing to avoid transferring torque to the manifold.
3 - Gas piping must not run in or through air ducts, clothes
chutes, chimneys or gas vents, dumb waiters or eleva
tor shafts. Center gas line through piping hole. Gas
line should not touch side of unit. See figures 61 and
62.
6 - In some localities, codes may require installation of a
manual main shut‐off valve and union (furnished by in
staller) external to the unit. Union must be of the
ground joint type.
IMPORTANT
Compounds used on threaded joints of gas piping
must be resistant to the actions of liquified petro
leum gases.
Leak Check
After gas piping is completed, carefully check all piping
connections (factory- and field-installed) for gas leaks. Use
a leak detecting solution or other preferred means.
Never use an open flame to test for gas leaks. Check all
connections using a commercially available soap solution
made specifically for leak detection.
The furnace must be isolated from the gas supply system
by closing its individual manual shut‐off valve during any
pressure testing of the gas supply system at pressures
greater than or equal to 1/2 psig (3.48 kPa, 14 inches w.c.).
MANUAL MAIN SHUT-OFF
VALVE WILL NOT HOLD
NORMAL TEST PRESSURE
1/8” N.P.T.
PLUGGED TAP
FIGURE 60
CAP
FURNACE
ISOLATE
GAS VALVE
IMPORTANT
When testing pressure of gas lines, gas valve must
be disconnected and isolated. See figure 60. Gas
valves can be damaged if subjected to pressures
greater than 1/2 psig (3.48 kPa).
4 - Piping should be sloped 1/4 inch per 15 feet (6mm per
5.6m) upward toward the gas meter from the furnace.
The piping must be supported at proper intervals, ev
ery 8 to 10 feet (2.44 to 3.05m), using suitable hangers
or straps. Install a drip leg in vertical pipe runs to serve as
a trap for sediment or condensate.
5 - A 1/8” N.P.T. plugged tap or pressure post is located
on the gas valve to facilitate test gauge connection.
See figure 66.
WARNING
FIRE OR EXPLOSION HAZARD
Failure to follow the safety warnings exactly could
result in serious injury, death, or property damage.
Never use an open flame to test for gas leaks. Check
all connections using a commercially available soap
solution made specifically for leak detection. Some
soaps used for leak detection are corrosive to cer
tain metals. Carefully rinse piping thoroughly after
leak test has been completed.
Page 38
Page 39
Left Side Piping
(Standard)
MANUAL
MAIN SHUT-OFF
VALV E
Right Side Piping
(Alternate)
MANUAL
MAIN SHUT-OFF
VALV E
GROUND
JOINT
UNION
MANUAL
MAIN SHUT-OFF
VALV E
GROUND
JOINT
UNION
DRIP LEG
DRIP LEG
Gas Valve
FIELD
PROVIDED
AND INSTALLED
NOTE - BLACK IRON PIPE ONLY TO BE ROUTED INSIDE OF CABINET
FIGURE 61
Horizontal Applications
Possible Gas Piping Configurations
MANUAL
MAIN SHUT-OFF
VALV E
GROUND
JOINT
UNION
DRIP LEG
Gas Valve
GROUND
JOINT
UNION
DRIP LEG
Horizontal Application
Left-Side Air Discharge
Horizontal Application
Right-Side Air Discharge
Gas Valve
FIELD
PROVIDED
AND INSTALLED
NOTE - BLACK IRON PIPE ONLY TO BE ROUTED INSIDE OF CABINET
FIGURE 62
Gas Valve
MANUAL
MAIN SHUT-OFF
VALV E
GROUND
JOINT
UNION
DRIP LEG
Page 39
Page 40
GAS PIPE CAPACITY - FT
TABLE 10
Nominal
Iron Pipe
Size
inches
(mm)
1/2
(12.7)
3/4
(19.05)
1
(25.4)
1-1/4
(31.75)
1-1/2
(38.1)
2
(50.8)
2-1/2
(63.5)
3
(76.2)
NOTE - Capacity given in cubic feet of gas per hour (kilo liters of gas per hour) and based on 0.60 specific gravity gas.
The unit is equipped with a field make-up box. The makeup box may be moved to the right side of the furnace to fa
cilitate installation. Secure the excess wire to the existing
ELECTROSTATIC DISCHARGE (ESD)
Precautions and Procedures
harness to protect it from damage.
Refer to figure 64 for field wiring, schematic wiring diagram
and troubleshooting.
CAUTION
Electrostatic discharge can affect elec
tronic components. Take precautions
to neutralize electrostatic charge by
touching your hand and tools to metal
prior to handling the control.
The power supply wiring must meet Class I restrictions.
Protected by either a fuse or circuit breaker, select circuit
protection and wire size according to unit nameplate.
NOTE - Unit nameplate states maximum current draw.
Maximum Over-Current Protection allowed is 15 AMP.
Holes are on both sides of the furnace cabinet to facilitate
wiring.
INTERIOR MAKE-UP BOX INSTALLATION
remove and relocate
plug to unused
opening on left side
Install a separate (properly sized) disconnect switch near
the furnace so that power can be turned off for servicing.
Before connecting the thermostat check to make sure the
wires will be long enough for servicing at a later date. Make
sure that thermostat wire is long enough to facilitate future
removal of blower for service.
MAKE-UP
BOX
Complete the wiring connections to the equipment. Use the
provided unit wiring diagram and the field wiring diagram
shown in figure 64. Use 18-gauge wire or larger that is suit
able for Class II rating for thermostat connections.
Electrically ground the unit according to local codes or, in
Right Side
the absence of local codes, according to the current Na
tional Electric Code (ANSI/NFPA No. 70) for the USA and
current Canadian Electric Code part 1 (CSA standard
C22.1) for Canada. A green ground wire is provided in the
field make-up box.
NOTE - The EL296UHE furnace contains electronic
FIGURE 63
components that are polarity sensitive. Make sure that the
furnace is wired correctly and is properly grounded.
56
(1.58)
117
(3.31)
220
(6.23)
452
677
1300
2080
3670
52
(1.47)
110
(3.11)
207
(5.86)
424
(12.00)
635
(17.98)
1220
(34.55)
1950
(55.22)
3450
(97.69)
100
(30.480)
50
(1.42)
104
(2.94)
195
(5.52)
400
(11.33)
600
(17.00)
1160
(32.844)
1840
(52.10)
3260
(92.31)
Page 40
Page 41
Accessory Terminals
One line voltage “ACC” 1/4” spade terminal is provided on
the furnace integrated control. See figure 65 for integrated
control configuration. This terminal is energized when the
indoor blower is operating. Any accessory rated up to one
amp can be connected to this terminal with the neutral leg
of the circuit being connected to one of the provided neutral
terminals. If an accessory rated at greater than one amp is
connected to this terminal, it is necessary to use an exter
nal relay.
An unpowered, normally open (dry) set of contacts with a
1/4” spade terminal “HUM” are provided for humidifier con
nections and may be connected to 24V or 120V. Any hu
midifier rated up to one amp can be connected to these ter
minals. In 120V humidifier applications the neutral leg of
the circuit can be connected to one of the provided neutral
terminals. This terminal is energized in the heating mode.
Install the room thermostat according to the instructions
provided with the thermostat. See figure 64 for thermostat
designations. If the furnace is being matched with a heat
pump, refer to the FM21 installation instruction or appropri
ate dual fuel thermostat instructions.
Indoor Blower Speeds
1 - When the thermostat is set to “FAN ON,” the indoor
blower will run continuously on the field selectable fan
speed (“LOW HEAT” is default) when there is no cool
ing or heating demand.
2 - When the EL296UHE is running in the heating mode,
the indoor blower will run on the 'LOW HEAT” or “HIGH
HEAT” speed per demand.
3 - When there is a cooling demand, the indoor blower will
run on the “LOW COOL” or “HIGH COOL” speed per
demand.
Generator Use - Voltage Requirements
The following requirements must be kept in mind when
specifying a generator for use with this equipment:
D The furnace requires 120 volts +
volts to 132 volts).
D The furnace operates at 60 Hz +
63 Hz).
10% (Range: 108
5% (Range: 57 Hz to
D The furnace integrated control requires both polarity
and proper ground. Both polarity and proper grounding
should be checked before attempting to operate the
furnace on either permanent or temporary power.
D Generator should have a wave form distortion of less
than 5% THD (total harmonic distortion).
On-Board Links and Diagnostic Push
Button (Figure 65)
WARNING
Carefully review all configuration information pro
vided. Failure to properly set DIP switches, jumpers
and on-board links can result in improper operation!
On-Board Link W914 Dehum
On-board link W914, is a clippable connection between ter
minals R and DS on the integrated control. W914 must be
cut when the furnace is installed with a thermostat which
features humidity control. If the link is not cut, terminal “DS”
will remain energized not allowing the blower to reduce to
low cool speed upon a call for dehumidification.
On-Board Link W951 Heat Pump (R to O)
On-board link W951 is a clippable connection between ter
minals R and O on the integrated control. W951 must be cut
when the furnace is installed in applications which include a
heat pump unit and a thermostat which features dual fuel
use. If the link is left intact, terminal “O” will remain ener
gized eliminating the HEAT MODE in the heat pump.
On-Board Link W915 2 Stage Compr (Y1 to Y2)
On-board link W915 is a clippable connection between ter
minals Y1 and Y2 on the integrated control. W915 must be
cut if two-stage cooling will be used. If the Y1 to Y2 link is
not cut the outdoor unit will operate in second-stage cool
ing only.
Diagnostic Push Button
The diagnostic push button is located adjacent to the
seven-segment diagnostic LED. This button is used to en
able the Error Code Recall “E” mode and the Flame Signal
“F” mode. Press the button and hold it to cycle through a
menu of options. Every five seconds a new menu item will
be displayed. When the button is released, the displayed
item will be selected. Once all items in the menu have been
displayed, the menu resumes from the beginning until the
button is released.
Page 41
Page 42
TYPICAL EL296UHE WIRING DIAGRAM
FIGURE 64
Page 42
Page 43
Integrated Control
24VAC Indoor
Blower Terminals
Flame Sense
LED
S4 DIP Switches
Diagnostic Push
Button
HUM
ACC
Ignitor and Combustion
Air Inducer
Neutrals
On Board Links
3/16” QUICK CONNECT TERMINALS
FLAME SENSE SIGNAL
HI COOL 24VAC
HI HEAT 24VAC
LO COOL 24VAC
LO HEAT 24VAC
PARK
PARK
COMMON 24VAC
1/4” QUICK CONNECT TERMINALS
NEUTRALS = 120 VAC NEUTRAL
HUM = UNPOWERED NORMALLY OPEN (DRY) CONTACTS
LI = 120 VAC INPUT TO CONTROL
ACC = 120 VAC OUTPUT TO OPTIONAL ACCESSORY
.............
THERMOSTAT CONNECTIONS (TB1)
DS = DEHUMIDIFICATION SIGNAL
W2 = HEAT DEMAND FROM 2ND STAGE T/STAT
W1 = HEAT DEMAND FROM 1ST STAGE T/STAT
R = CLASS 2 VOLTAGE TO THERMOSTAT
G = MANUAL FAN FROM T'STAT
C = THERMOSTAT SIGNAL GROUND CONNECTED TO
TRANSFORMER GRD (TR) & CHASIS GROUND (GRD)
Y1 = THERMOSTAT 1ST STAGE COOL SIGNAL
Y2 = THERMOSTAT 2ND STAGE COOL SIGNAL
O = THERMOSTAT SIGNAL TO HEAT PUMP
REVERSING VALVE
DH = NOT USED
L = NOT USED
FIGURE 65
Page 43
Page 44
Integrated Control DIP Switch Settings
EL296UHE units are equipped with a two-stage integrated
control. This control manages ignition timing, heating
mode fan off delays and indoor blower speeds based on
selections made using the control dip switches and jump
ers. The control includes an internal watchguard feature
which automatically resets the ignition control when it has
been locked out. After one hour of continuous thermostat
demand for heat, the watchguard will break and remake
thermostat demand to the furnace and automatically reset
the control to relight the furnace.
Heating Operation DIP Switch Settings
Switch 1 -- Thermostat Selection -- This unit may be
used with either a single-stage or two-stage thermostat.
The thermostat selection is made using a DIP switch which
must be properly positioned for the particular application.
The DIP switch is factory-positioned for use with a twostage thermostat. If a single-stage thermostat is to be used,
the DIP switch must be repositioned.
a- Select “OFF” for two-stage heating operation con
trolled by a two-stage heating thermostat (factory set
ting);
b - Select “ON” for two-stage heating operation con
trolled by a single-stage heating thermostat. This set
ting provides a timed delay before second-stage heat
is initiated.
Switch 2 -- Second Stage Delay (Used with SingleStage Thermostat Only) -- This switch is used to deter
mine the second stage on delay when a single-stage ther
mostat is being used. The switch is factory-set in the OFF
position, which provides a 7-minute delay before secondstage heat is initiated. If the switch is toggled to the ON
position, it will provide a 12-minute delay before secondstage heat is initiated. This switch is only activated when
the thermostat selector jumper is positioned for SINGLEstage thermostat use.
The blower-on delay of 30 seconds is not adjustable. The
blower-off delay (time that the blower operates after the
heating demand has been satisfied) can be adjusted by
moving switches 3 and 4 on the integrated control. The unit
is shipped from the factory with a blower-off delay of 90 se
conds. The blower off delay affects comfort and is adjust
able to satisfy individual applications. Adjust the blower off
delay to achieve a supply air temperature between 90° and
110°F at the exact moment that the blower is de-energized.
Longer off delay settings provide lower supply air tempera
tures; shorter settings provide higher supply air temperatu
res.Table 11 provides the blower off timings that will result
from different switch settings.
Blower Off Heating Mode Delay Switch Settings
Blower Off Delay
(Seconds)
60OnOff
90 (Factory)OffOff
120OffOn
180OnOn
Switch 5 -- Cooling Mode Blower-Off Delay-- The unit is
shipped from the factory with the dip switch positioned OFF
for a 45 second delay. Table 12 provides the cooling mode
off delay settings.
Blower Off Cooling Mode Delay Switch Settings
Blower Off Delay
(Seconds)
45 (Factory)
2On
Switches 6 and 7 -- Continuous Fan Mode -- Continuous
fan speed can be controlled by changing DIP switch posi
tions. Table 13 below provides DIP switch settings for con
tinuous fan mode.
Continuous Fan Mode Settings
Continuous Fan
Mode
Low Heat Speed
(factory)
Low Cool SpeedOffOn
High High SpeedOnOff
High Cool SpeedOnOn
TABLE 11
Switch 3Switch 4
TABLE 12
Switch 5
Off
TABLE 13
Switch 6Switch 7
OffOff
Page 44
Page 45
Thermostat
1 Heat / 1 Cool
NOTE - Use DIP
switch 2 to set
second-stage
heat ON delay.
OFF-7 minutes.
ON-12 minutes.
TABLE 14
EL296 Field Wiring Applications With Conventional Thermostat
DIP Switch Settings and On-Board Links (See figure 65)
DIP Switch 1
Thermostat
Heating
On Board Links Must Be Cut To Select
System Options
Stages
ON
DO NOT CUT ANY
ON-BOARD LINKS
Wiring Connections
S1
T'STAT
*Not required on all units
FURNACE
TERM. STRIP
OUTDOOR
UNIT
*
1 Heat / 2 Cool
NOTE - Use DIP
switch 2 to set
second-stage
heat ON delay.
OFF-7 minutes.
ON-12 minutes.
1 Heat / 2 Cool
with t'stat with
humidity control
NOTE - Use DIP
switch 2 to set
second-stage
heat ON delay.
OFF-7 minutes.
ON-12 minutes.
ON
ON
CUT ON-BOARD LINK
W915
2 STAGE
COMPR
CUT ON-BOARD LINK
W915
2 STAGE
COMPR
CUT ON-BOARD LINK
W914
DEHUM
DEHUM
DEHUM
S1
T'STAT
*Not required on all units
S1
T'STAT
*Not required on all units
FURNACE
TERM. STRIP
*
FURNACE
TERM. STRIP
o
OUTDOOR
UNIT
OUTDOOR
UNIT
*
Page 45
Page 46
EL296 Field Wiring Applications With Conventional Thermostat (Continued)
DIP Switch Settings and On-Board Links (See figure 65)
DIP Switch 1
Thermostat
Thermostat
Heating
Stages
2 Heat / 2 CoolOFF
TABLE 14
On Board Links Must Be Cut To Select
System Options
CUT ON-BOARD LINK
W915
2 STAGE
COMPR
DEHUM
Wiring Connections
S1
T'STAT
*Not required on all units
FURNACE
TERM. STRIP
OUTDOOR
*
UNIT
2 Heat / 2 Cool
with t'stat with
humidity control
2 Heat / 1 Cool
with t'stat with
humidity control
OFF
OFF
CUT ON-BOARD LINK
W915
2 STAGE
COMPR
CUT ON-BOARD LINK
W914
DEHUM
CUT ON-BOARD LINK
W914
DEHUM
S1
T'STAT
*Not required on all units
S1
T'STAT
*Not required on all units
FURNACE
TERM. STRIP
o
FURNACE
TERM. STRIP
o
OUTDOOR
UNIT
*
OUTDOOR
UNIT
*
2 Heat / 1 CoolOFF
DO NOT CUT ANY
ON-BOARD LINKS
Page 46
DEHUM
S1
T'STAT
*Not required on all units
FURNACE
TERM. STRIP
OUTDOOR
UNIT
*
Page 47
Thermostat
Dual Fuel
Single Stage
Heat Pump
ComfortSense
7000 L7724U
thermostat w/
dual fuel capa
bilities
Capable of 2
stage gas heat
control
TABLE 14
EL296 Field Wiring Applications With Conventional Thermostat (Continued)
DIP Switch Settings and On-Board Links (figure 65)
DIP Switch 1
Thermostat
Heating
On Board Links Must Be Cut To Select
System Options
Wiring Connections
Stages
FURNACE
TERM. STRIP
OFF
CUT ON-BOARD LINK
W951
HEAT
PUMP
DEHUM
L7724U
T'STAT
H
L
Y2
D
B
HEAT PUMP
67M41*
L
Y
Y2
Dual Fuel
Two Stage
Heat Pump
ComfortSense
OFF
CUT ON-BOARD LINK
W915
2 STAGE
COMPR
L7724U
T'STAT
H
FURNACE
TERM. STRIP
HEAT PUMP
67M41*
7000 L7724U
thermostat w/
dual fuel capa
bilities
Capable of 2
stage gas heat
CUT ON-BOARD LINK
W951
HEAT
PUMP
DEHUM
L
Y2
control
D
B
* Connect W1 to W1 ONLY if using defrost tempering kit 67M41
NOTE - Do NOT make a wire connection between the room thermostat L terminal and the L terminal of the EL296
integrated control.
L
Y2
out blue
Page 47
Page 48
Thermostat
Dual Fuel
Single Stage
Heat Pump
ComfortSense
7000 L7742U
thermostat w/
dual fuel capa
bilities
Capable of 2
stage gas heat
control w/dehu
midification
control
TABLE 14
EL296 Field Wiring Applications With Conventional Thermostat (Continued)
DIP Switch Settings and On-Board Links (figure 65)
DIP Switch 1
Thermostat
Heating
On Board Links Must Be Cut To Select
System Options
Wiring Connections
Stages
FURNACE
TERM. STRIP
OFF
CUT ON-BOARD LINK
W951
HEAT
PUMP
CUT ON-BOARD LINK
W914
DEHUM
L7742U
T'STAT
H
L
Y2
D
B
HEAT PUMP
67M41*
L
Y
Y2
Dual Fuel
Two Stage
Heat Pump
ComfortSense
7000 L7742U
thermostat w/
dual fuel capa
bilities
Capable of 2
stage gas heat
OFF
CUT ON-BOARD LINK
W915
2 STAGE
COMPR
CUT ON-BOARD LINK
W951
HEAT
PUMP
CUT ON-BOARD LINK
W914
DEHUM
L7742U
T'STAT
H
L
Y2
FURNACE
TERM. STRIP
HEAT PUMP
67M41*
control w/dehu
midification
D
B
Y2
* Connect W1 to W1 ONLY if using defrost tempering kit 67M41
NOTE - Do NOT make a wire connection between the room thermostat L terminal and the L terminal of the EL296
integrated control.
L
Y2
out blue
Page 48
Page 49
Unit Start-Up
FOR YOUR SAFETY READ BEFORE OPERATING
WARNING
Do not use this furnace if any part has been under
water. A flood-damaged furnace is extremely dan
gerous. Attempts to use the furnace can result in
fire or explosion. Immediately call a qualified ser
vice technician to inspect the furnace and to replace
all gas controls, control system parts, and electrical
parts that have been wet or to replace the furnace,
if deemed necessary.
WARNING
Danger of explosion. Can cause injury
or product or property damage. Should
the gas supply fail to shut off or if
overheating occurs, shut off the gas
valve to the furnace before shutting off
the electrical supply.
CAUTION
Before attempting to perform any service or mainte
nance, turn the electrical power to unit OFF at dis
connect switch.
BEFORE LIGHTING the unit, smell all around the fur
nace area for gas. Be sure to smell next to the floor be
cause some gas is heavier than air and will settle on the
floor.
The gas valve on the EL296UHE is equipped with a gas
control switch (lever). Use only your hand to move
switch. Never use tools. If the the switch will not move by
hand, do not try to repair it. Force or attempted repair may
result in a fire or explosion.
Placing the furnace into operation:
EL296UHE units are equipped with an automatic hot sur
face ignition system. Do not
burners on this furnace. Each time the thermostat calls
for heat, the burners will automatically light. The ignitor
does not get hot when there is no call for heat on these
units.
Priming Condensate Trap
The condensate trap should be primed with water prior to
start-up to ensure proper condensate drainage. Either
pour 10 fl. oz. (300 ml) of water into the trap, or follow
these steps to prime the trap:
1 - Follow the lighting instructions to place the unit into op
eration.
2 - Set the thermostat to initiate a heating demand.
3 - Allow the burners to fire for approximately 3 minutes.
4 - Adjust the thermostat to deactivate the heating de
mand.
attempt to manually light
5 - Wait for the combustion air inducer to stop. Set the
thermostat to initiate a heating demand and again al
low the burners to fire for approximately 3 minutes.
6 - Adjust the thermostat to deactivate the heating de
mand and wait for the combustion air inducer to stop.
At this point, the trap should be primed with sufficient
water to ensure proper condensate drain operation.
WARNING
If you do not follow these instructions exactly, a fire
or explosion may result causing property damage,
personal injury or death.
Gas Valve Operation (Figure 66)
1 - STOP! Read the safety information at the beginning of
this section.
2 - Set the thermostat to the lowest setting.
3 - Turn off all electrical power to the unit.
4 - This furnace is equipped with an ignition device which
automatically lights the burners. Do not try to light the
burners by hand.
5 - Remove the access panel.
6 - Move gas valve switch to OFF. See figure 66.
7 - Wait five minutes to clear out any gas. If you then smell
gas, STOP! Immediately call your gas supplier from a
neighbor's phone. Follow the gas supplier's instruc
tions. If you do not smell gas go to next step.
8 - Move gas valve switch to ON. See figure 66.
INLET PRESSURE POST
GAS VALVE SHOWN IN ON POSITION
9 - Replace the access panel.
10- Turn on all electrical power to to the unit.
11- Set the thermostat to desired setting.
NOTE - When unit is initially started, steps 1 through 11
may need to be repeated to purge air from gas line.
12- If the appliance will not operate, follow the instructions
“Turning Off Gas to Unit” and call your service techni
cian or gas supplier.
Turning Off Gas to Unit
1 - Set the thermostat to the lowest setting.
2 - Turn off all electrical power to the unit if service is to be
performed.
3 - Remove the access panel.
MANIFOLD
PRESSURE POST
FIGURE 66
HIGH FIRE ADJUSTMENT
SCREW
(under cap)
Page 49
Page 50
4 - Move gas valve switch to OFF.
5 - Replace the access panel.
Failure To Operate
If the unit fails to operate, check the following:
1 - Is the thermostat calling for heat?
2 - Are access panels securely in place?
3 - Is the main disconnect switch closed?
4 - Is there a blown fuse or tripped breaker?
5 - Is the filter dirty or plugged? Dirty or plugged filters will
cause the limit control to shut the unit off.
6 - Is gas turned on at the meter?
7 - Is the manual main shut‐off valve open?
8 - Is the internal manual shut‐off valve open?
9 - Is the unit ignition system in lockout? If the unit locks out
again, inspect the unit for blockages.
Heating Sequence Of Operation
1 - When thermostat calls for heat, combustion air inducer
starts.
2 - Combustion air pressure switch proves blower opera
tion. Switch is factory set and requires no adjustment.
3 - After a 15-second prepurge, the hot surface ignitor en
ergizes.
4 - After a 20-second ignitor warm-up period, the gas
valve solenoid opens. A 4-second trial for ignition peri
od begins.”
5 - Gas is ignited, flame sensor proves the flame, and the
combustion process continues.
6 - If flame is not detected after first ignition trial, the igni
tion control will repeat steps 3 and 4 four more times
before locking out the gas valve (“WATCHGUARD”
flame failure mode). The ignition control will then auto
matically repeat steps 1 through 6 after 60 minutes.
To interrupt the 60-minute “WATCHGUARD” period,
move thermostat from “Heat” to “OFF” then back to
“Heat”. Heating sequence then restarts at step 1.
Gas Pressure Adjustment
Gas Flow (Approximate)
TABLE 15
GAS METER CLOCKING CHART
Seconds for One Revolution
EL296
Unit
-04580160200400
-07055110136272
-0904182102204
-110336682164
-135275468136
Natural-1000 btu/cu ft LP-2500 btu/cu ft
NaturalLP
1 cu ft
Dial
2 cu ft
Dial
1 cu ft
Dial
2 cu ft
DIAL
Furnace should operate at least 5 minutes before check
ing gas flow. Determine time in seconds for two revolu
tions of gas through the meter. (Two revolutions assures a
more accurate time.) Divide by two and compare to time
in table 15. If manifold pressure matches table 17 and rate
is incorrect, check gas orifices for proper size and re
striction. Remove temporary gas meter if installed.
NOTE - To obtain accurate reading, shut off all other gas
appliances connected to meter.
Supply Pressure Measurement
An inlet post located on the gas valve provides access to
the supply pressure. See figure 66. Back out the 3/32 hex
screw one turn, connect a piece of 5/16 tubing and connect
to a manometer to measure supply pressure. See table 17
for supply line pressure.
On multiple unit installations, each unit should be checked
separately, with and without units operating. Supply pres
sure must fall within range listed in table 17.
Manifold Pressure Measurement
NOTE - Pressure test adapter kit (10L34) is available from
Lennox to facilitate manifold pressure measurement.
A manifold pressure post located on the gas valve provides
access to the manifold pressure. See figure 66. Back out
the 3/32 hex screw one turn, connect a piece of 5/16 tubing
and connect to a manometer to measure manifold pres
sure.
To correctly measure manifold pressure, the differential
pressure between the positive gas manifold and the nega
tive burner box must be considered.
1 - Connect the test gauge positive side “+“ to manifold
pressure tap on gas valve as noted above.
2 - Tee into the gas valve regulator vent hose and connect
to test gauge negative “-”.
3 - Ignite unit on low fire and let run for 5 minutes to allow
for steady state conditions.
4 - After allowing unit to stabilize for 5 minutes, record
manifold pressure and compare to value given in table
17.
5 - If necessary, make adjustments. Figure 66 shows
location of high fire and low fire adjustment screws.
6 - Repeat steps 3, 4 and 5 on high fire. See values in
table 17.
NOTE - Shut unit off and remove manometer as soon as an
accurate reading has been obtained. Re-start unit and
check gas valve for gas leaks.
Page 50
Page 51
Proper Combustion
Furnace should operate minimum 15 minutes with correct
manifold pressure and gas flow rate before checking com
bustion. Take combustion sample beyond the flue outlet
and compare to the tables below.
TABLE 16
EL296
Model
CO2%
Low FireHigh FireLow FireHigh Fire
For Nat
0455.4 - 6.47.5 - 8.56.4 - 7.48.8 - 9.8
0705.3 - 6.37.4 - 8.46.3 - 7.38.7 - 9.7
0905.8 - 6.87.6 - 8.66.8 - 7.88.9 - 9.9
1106.1 - 7.18.0 - 9.07.1 - 8.19.3 - 10.3
1356.1 - 7.17.8 - 8.87.1 - 8.29.1 - 10.1
The maximum carbon monoxide reading should not exceed 50 ppm.
CO2%
For L.P
TABLE 17
Manifold and Supply Line Pressure 0-10,000ft.
High Altitude Information
NOTE - In Canada, certification for installations at eleva
tions over 4500 feet (1372 m) is the jurisdiction of local au
thorities.
Units may be installed at altitudes up to 10,000 ft. above
sea level without manifold adjustment. Units installed at al
titude of 4501 - 10,000 feet (1373 to 3048m) may require a
pressure switch change which can be ordered separately.
Table 18 lists conversion kit and pressure switch require
ments at varying altitudes.
The combustion air pressure switch is factory-set and re
quires no adjustment.
EL296
Unit
All Sizes
NOTE -
A natural to L.P. propane gas changeover kit is necessary to convert this unit. Refer to the changeover kit installation instruction for the conversion
procedure.
Gas
Natural1.73.54.510.5
LP/propane4.910.011.013.0
Manifold Pressure in.wg.Supply Line Pressure in. w.g.
Low FireHigh FireMinMax
TABLE 18
LP/Propane Conversion Kit and Pressure Switch Requirements at Varying Altitudes
EL296
Unit
-045
Natural to
LP/Propane
0 - 7500 ft
(0 - 2286m)
High Altitude
Natural Burner
Orifice Kit
7501 - 10,000 ft
(2286 - 3038m)
High Altitude
LP/Propane Burner
Orifice Kit
7501 - 10,000 ft
(2286 - 3038m)
High Altitude Pressure Switch
4501 - 7500 ft
(1373 - 2286m)
7501 -10,000 ft
(2286 - 3048m)
93W8193W84
-07093W8093W85
-09093W8293W80
*78W9373W37*78W96
-11093W8093W85
-13593W8393W85
* Conversion requires installation of a gas valve manifold spring which is provided with the gas conversion kit.
Pressure switch is factory set. No adjustment necessary. All models use the factory-installed pressure switch from 0-4500 feet (0-1370 m).
Page 51
Page 52
Testing for Proper Venting and Sufficient Combustion Air for Non-Direct Vent Applications
horizontal pitch. Determine there is no blockage or re
WARNING
CARBON MONOXIDE POISONING HAZARD!
Failure to follow the steps outlined below for each
appliance connected to the venting system being
placed into operation could result in carbon monox
ide poisoning or death.
The following steps shall be followed for each ap
pliance connected to the venting system being
placed into operation, while all other appliances con
nected to the venting system are not in operation.
After the EL296UHE gas furnace has been started, the fol
lowing test should be conducted to ensure proper venting
and sufficient combustion air has been provided to the
EL296UHE as well as to other gas‐fired appliances which
are separately vented.
If a EL296UHE furnace replaces a Category I furnace
which was commonly vented with another gas appliance,
the size of the existing vent pipe for that gas appliance must
be checked. Without the heat of the original furnace flue
products, the existing vent pipe is probably oversized for
the single water heater or other appliance. The vent should
be checked for proper draw with the remaining appliance.
The test should be conducted while all appliances (both in
operation and those not in operation) are connected to the
venting system being tested. If the venting system has
been installed improperly, or if provisions have not been
made for sufficient amounts of combustion air, corrections
must be made as outlined in the previous section.
1 - Seal any unused openings in the venting system.
2 - Visually inspect the venting system for proper size and
striction, leakage, corrosion, or other deficiencies
which could cause an unsafe condition.
3 - To the extent that it is practical, close all building doors
and windows and all doors between the space in which
the appliances connected to the venting system are lo
cated and other spaces of the building.
4 - Close fireplace dampers.
5 - Turn on clothes dryers and any appliances not con
nected to the venting system. Turn on any exhaust
fans, such as range hoods and bathroom exhausts, so
they will operate at maximum speed. Do not operate a
summer exhaust fan.
6 - Follow the lighting instruction to place the appliance
being inspected into operation. Adjust thermostat so
appliance will operate continuously.
7 - Use the flame of match or candle to test for spillage of
flue gases at the draft hood relief opening after 5 min
utes of main burner operation.
8 - If improper venting is observed during any of the
above tests, the venting system must be corrected or
sufficient combustion/make‐up air must be provided.
The venting system should be re‐sized to approach
the minimum size as determined by using the ap
propriate tables in appendix G in the current standards
of the National Fuel Gas Code ANSI-Z223.1/NPFA 54
in the U.S.A., and the appropriate Natural Gas and
Propane appliances venting sizing tables in the cur
rent standard of the CSA-B149 Natural Gas and Pro
pane Installation Codes in Canada.
9 - After determining that each appliance remaining
connected to the common venting system properly
vents when tested as indicated in step 3, return
doors, windows, exhaust fans, fireplace dampers
and any other gas‐burning appliance to their previous
condition of use.
Page 52
Page 53
Other Unit Adjustments
Primary Limit.
The primary limit is located on the heating compartment
vestibule panel. This limit is factory set and requires no ad
justment.
Flame Rollout Switches (Two)
These manually reset switches are located on the front of
the burner box.
Pressure Switch
The pressure switch is located in the heating compartment
on the cold end header box. This switch checks for proper
combustion air inducer operation before allowing ignition
trial. The switch is factory-set and must not be adjusted.
Temperature Rise
Place the unit into operation with a second-stage heating
demand. After supply and return air temperatures have
stabilized, check the temperature rise. If necessary, adjust
the heating blower speed to maintain the temperature rise
within the range shown on the unit nameplate. Increase the
blower speed to decrease the temperature rise. Decrease
the blower speed to increase the temperature rise. Failure
to properly adjust the temperature rise may cause erratic
limit operation.
Electrical
1 - Check all wiring for loose connections.
2 - Check for the correct voltage at the furnace (furnace
operating). Correct voltage is 120VAC +
3 - Check amp-draw on the blower motor with blower ac
cess panel in place.
Unit Nameplate__________Actual__________
Exhaust and Air Intake Pipe
1 - Check exhaust and air intake connections for tightness
and to make sure there is no blockage.
2 - Is pressure switch closed? Obstructed exhaust pipe
will cause unit to shut off at pressure switch. Check ter
mination for blockages.
3 - Obstructed pipe or termination may cause rollout
switches to open. Reset manual flame rollout switches
on burner box assembly if necessary.
10%
Heating Sequence of Operation
Electronic Ignition
The two-stage, variable speed integrated control used in
EL296UHE units has an added feature of an internal Watch
guard control. The feature serves as an automatic reset de
vice for ignition control lockout caused by ignition failure. Af
ter one hour of continuous thermostat demand for heat, the
Watchguard will break and remake thermostat demand to
the furnace and automatically reset the control to begin the
ignition sequence.
NOTE - The ignition control thermostat selection DIP switch is
factory-set in the “TWO-STAGE” position.
Applications Using a Two-Stage Thermostat
A - Heating Sequence -- Integrated Control Thermostat
Selection DIP Switch 1 OFF in “Two-Stage” Position
(Factory Setting)
1 - On a call for heat, thermostat first-stage contacts close
sending a signal to the integrated control. The inte
grated control runs a self‐diagnostic program and
checks high temperature limit switches for normally
closed contacts and pressure switches for normally
open contacts. The combustion air inducer is ener
gized at low speed.
2 - Once the control receives a signal that the low pres
sure switch has closed, the combustion air inducer be
gins a 15-second pre-purge in low speed.
NOTE - If the low fire pressure switch does not close
the combustion air inducer will switch to high fire. After
a 15 second pre-purge the high fire pressure switch
will close and the unit will begin operation on high fire.
After 10 to 20 seconds of high fire operation the unit
will switch to low fire..
3 - After the pre-purge is complete, a 20-second initial ig
nitor warm-up period begins. The combustion air in
ducer continues to operate at low speed.
4 - After the 20-second warm-up period has ended, the gas
valve is energized on low fire (first stage) and ignition oc
curs. At the same time, the control module sends a sig
nal to begin an indoor blower 30-second ON-delay.
When the delay ends, the indoor blower motor is ener
gized on the low fire heating speed, the HUM contacts
close energizing the humidifier and 120V ACC termi
nal is energized. The furnace will continue this opera
tion as long as the thermostat has a first-stage heating
demand.
5 - If second-stage heat is required, the thermostat sec
ond-stage heat contacts close and send a signal to the
integrated control. The integrated control initiates a
30-second second-stage recognition delay.
6 - At the end of the recognition delay, the integrated con
trol energizes the combustion air inducer at high
speed. The control also checks the high fire (second
stage) pressure switch to make sure it is closed. The
high fire (second stage) gas valve is energized and the
indoor blower motor is energized for operation at the
high fire heating speed.
7 - When the demand for high fire (second stage) heat is
satisfied, the combustion air inducer is switched to the
low-fire heating speed and the high-fire (second
stage) gas valve is de-energized. The low-fire (first
stage) gas valve continues operation. The indoor
blower motor is switched to the low-fire heating speed.
8 - When the thermostat demand for low-fire (first stage)
heat is satisfied, the gas valve is de-energized and the
field-selected indoor blower off delay begins. The
combustion air inducer begins a 5-second post-purge
period.
9 - When the combustion air post-purge period is com
plete, the inducer, the HUM contacts as well as the
120V ACC terminals are de-energized. The indoor
blower is de-energized at the end of the off delay.
Page 53
Page 54
Applications Using A Single-Stage Thermostat
B - Heating Sequence -- Integrated Control Thermostat
Selection DIP Switch 1 ON in “Single-Stage” Position
NOTE - In these applications, two-stage heat will be initi
ated by the integrated control if heating demand has not
been satisfied after the field adjustable period (7 or 12 min
utes).
1 - On a call for heat, thermostat first-stage contacts close
sending a signal to the integrated control. The inte
grated control runs a self‐diagnostic program and
checks high temperature limit switches for normally
closed contacts and pressure switches for normally
open contacts. The combustion air inducer is ener
gized at low speed.
2 - Once the control receives a signal that the low pres
sure switch has closed, the combustion air inducer be
gins a 15-second pre-purge in low speed.
NOTE - If the low fire pressure switch does not close
the combustion air inducer will switch to high fire. After
a 15 second pre-purge the high fire pressure switch
will close and the unit will begin operation on high fire.
After 10 to 20 seconds of high fire operation the unit
will switch to low fire.
3 - After the pre-purge is complete, a 20-second initial ig
nitor warm-up period begins. The combustion air in
ducer continues to operate at low speed.
4 - After the 20-second warm-up period has ended, the gas
valve is energized on low fire (first stage) and ignition oc
curs. At the same time, the control module sends a sig
nal to begin an indoor blower 30-second ON-delay.
When the delay ends, the indoor blower motor is ener
gized on the low fire heating speed and the HUM con
tacts are energized. The integrated control also initi
ates a second-stage on delay (factory-set at 7
minutes; adjustable to 12 minutes).
5 - If the heating demand continues beyond the second-
stage on delay, the integrated control energizes the
combustion air inducer at high speed. The control also
checks the high fire (second stage) pressure switch to
make sure it is closed. The high fire (second stage)
gas valve is energized and the indoor blower motor is
energized for operation at the high fire heating speed.
6 - When the thermostat heating demand is satisfied, the
combustion air inducer begins a 5-second low speed
post-purge. The field-selected indoor blower off delay
begins. The indoor blower operates at the low-fire
heating speed.
7 - When the combustion air post-purge period is com
plete, the inducer, the HUM contacts as well as the
120V ACC terminals are de-energized. The indoor
blower is de-energized at the end of the off delay.
Repair Parts List
The following repair parts are available through Lennox
dealers. When ordering parts, include the complete fur
nace model number listed on the CSA nameplate -- Exam
ple: EL296UH045XE24B-01. All service must be per
formed by a licensed professional installer (or
equivalent), service agency, or gas supplier.
Cabinet Parts
Outer access panel
Blower access panel
Top Cap
Control Panel Parts
Transformer
Integrated control board
Door interlock switch
Blower Parts
Blower wheel
Motor
Motor mounting frame
Motor capacitor
Blower housing cutoff plate
Heating Parts
Flame Sensor
Heat exchanger assembly
Gas manifold
Combustion air inducer
Gas valve
Main burner cluster
Main burner orifices
Pressure switch
Ignitor
Primary limit control
Flame rollout switches
Page 54
Page 55
Service
WARNING
ELECTRICAL SHOCK, FIRE,
OR EXPLOSION HAZARD.
Failure to follow safety warnings exactly could result
in dangerous operation, serious injury, death or
property damage.
Improper servicing could result in dangerous opera
tion, serious injury, death, or property damage.
Before servicing, disconnect all electrical power to
furnace.
When servicing controls, label all wires prior to dis
connecting. Take care to reconnect wires correctly.
Verify proper operation after servicing.
At the beginning of each heating season, system should be
checked as follows by a qualified service technician:
Blower
Check the blower wheel for debris and clean if necessary.
The blower motors are prelubricated for extended bearing
life. No further lubrication is needed.
WARNING
The blower access panel must be securely in place
when the blower and burners are operating. Gas
fumes, which could contain carbon monoxide, can
be drawn into living space resulting in personal inju
ry or death.
Filters
All air filters are installed external to the unit. Filters should
be inspected monthly. Clean or replace the filters when
necessary to ensure proper furnace operation. Table 1
lists recommended filter sizes.
Exhaust and air intake pipes
Check the exhaust and air intake pipes and all connections
for tightness and to make sure there is no blockage.
NOTE - After any heavy snow, ice or frozen fog event the
furnace vent pipes may become restricted. Always check
the vent system and remove any snow or ice that may be
obstructing the plastic intake or exhaust pipes.
Electrical
1 - Check all wiring for loose connections.
2 - Check for the correct voltage at the furnace (furnace
operating).
3 - Check amp-draw on the blower motor.
Motor Nameplate__________Actual__________
Winterizing and Condensate Trap Care
1 - Turn off power to the furnace.
2 - Have a shallow pan ready to empty condensate water.
3 - Remove the clean out cap from the condensate trap
and empty water. Inspect the trap then reinstall the
clean out cap.
Cleaning The Burner Assembly
If cleaning the burner assembly becomes necessary, fol
low the steps below:
1 - Turn off electrical and gas power supplies to furnace.
Remove upper and lower furnace access panels.
2 - Disconnect the wires from the gas valve.
3 - Remove the burner box cover (if equipped).
4 - Disconnect the gas supply line from the gas valve. Re
move gas valve/manifold assembly.
5 - Mark and disconnect sensor wire from the sensor. Dis
connect wires from flame rollout switches.
6 - Disconnect combustion air intake pipe. It may be nec
essary to cut the existing pipe to remove burner box
assembly.
7 - Remove four screws which secure burner box assem
bly to vest panel. Remove burner box from the unit.
8 - Use the soft brush attachment on a vacuum cleaner to
gently clean the face of the burners. Visually inspect
the inside of the burners and crossovers for any block
age caused by foreign matter. Remove any blockage.
9 - Reinstall the burner box assembly using the existing
four screws. Make sure that the burners line up in the
center of the burner ports.
10 - Reconnect the sensor wire and reconnect the 2-pin
plug to the ignitor wiring harness. Reconnect wires to
flame rollout switches.
11 - Reinstall the gas valve manifold assembly. Reconnect
the gas supply line to the gas valve. Reinstall the burn
er box cover.
12 - Reconnect wires to gas valve.
13 - Replace the blower compartment access panel.
14 - Refer to instruction on verifying gas and electrical con
nections when re-establishing supplies.
15 - Follow lighting instructions to light and operate fur
nace for 5 minutes to ensure that heat exchanger is
clean and dry and that furnace is operating properly.
16 - Replace heating compartment access panel.
Page 55
Page 56
Start-Up & Performance Check List
Furnace:
Model Number_______________
UNIT SET UP
(typical)
Serial Number_________________
SUPPLY
Line Voltage
2
4
1
GAS SUPPLY
Natural Gas
LP Propane Gas
AIR
3
Piping Connections Tight
Leak Tested
2
Supply Line Pressure “W.C.________
1
Gas Supply Pressure
1
Flter
RETURN AIR
2
INTAKE / EXHAUST PIPE
All Joints Primed and Glued
Terminations Installed Properly
Horizontal Pipes Sloped (if applicable)
Condensate Trap Primed / Line Sloped
Pipes Supported
Heat Cable Installed and Operable (if applicable)
DUCT SYSTEM
3
SUPPLY AIR DUCT
Sealed
Insulated (if necessary)
RETURN DUCT
Sealed
Filter Installed and Clean
Grilles Unobstructed
VOLTAGE CHECK
4
Supply Voltage _____
Electrical Connections Tight
Page 56
Page 57
HEATING MODE
GAS MANIFOLD PRESSURE “W.C._____
1
UNIT OPERATION
COOLING MODE
INDOOR BLOWER AMPS______
3
2
COMBUSTION SAMPLE CO
INDOOR BLOWER AMPS______
3
TEMPERATURE RISE
4
Supply Duct Temperature ________
Return Duct Temperature
Temperature Rise = ________
TOTAL EXTERNAL STATIC
5
Supply External Static _______
Return External Static + ______
Total External Static = _______
6
CONDENSATE LINE
Leak Free
7
VENT PIPE
Leak Free
Combustion CO
2
2%______
_
_____
CO PPM_______
TEMPERATURE DROP
4
Return Duct Temperature _________
Supply Duct Temperature
Revise NFPA-54 section 10.8.3 to add the following re
quirements:
For all side wall, horizontally vented, gas-fueled equipment
installed in every dwelling, building or structure used in
whole or in part for residential purposes, including those
owned or operated by the Commonwealth and where the
side wall exhaust vent termination is less than seven (7)
feet above the finished grade in the area of the venting, in
cluding but not limited to decks and porches, the following
requirements shall be satisfied:
1 - INSTALLATION OF CARBON MONOXIDE DETEC
TORS. At the time of installation of the side wall, hori
zontally vented, gas-fueled equipment, the installing
plumber or gasfitter shall observe that a hard-wired
carbon monoxide detector with an alarm and battery
backup is installed on the floor level where the gas
equipment is to be installed. In addition, the installing
plumber or gasfitter shall observe that a battery-oper
ated or hard-wired carbon monoxide detector with an
alarm is installed on each additional level of the dwell
ing, building or structure served by the side wall, hori
zontally vented, gas-fueled equipment. It shall be the
responsibility of the property owner to secure the ser
vices of qualified licensed professionals for the instal
lation of hard-wired carbon monoxide detectors.
a - In the event that the side wall, horizontally vented,
gas-fueled equipment is installed in a crawl space
or an attic, the hard-wired carbon monoxide detec
tor with alarm and battery back-up may be installed
on the next adjacent floor level.
b - In the event that the requirements of this subdivi
sion cannot be met at the time of completion of
installation, the owner shall have a period of thirty
(30) days to comply with the above requirements;
provided, however, that during said thirty (30) day
period, a battery-operated carbon monoxide detec
tor with an alarm shall be installed.
2 - APPROVED CARBON MONOXIDE DETECTORS.
Each carbon monoxide detector as required in accor
dance with the above provisions shall comply with
NFPA 720 and be ANSI/UL 2034 listed and IAS certi
fied.
3 - SIGNAGE. A metal or plastic identification plate shall
be permanently mounted to the exterior of the building
at a minimum height of eight (8) feet above grade di
rectly in line with the exhaust vent terminal for the hori
zontally vented, gas-fueled heating appliance or
equipment. The sign shall read, in print size no less
than one-half (1/2) inch in size, “GAS VENT DIRECT
LY BELOW. KEEP CLEAR OF ALL OBSTRUC
TIONS.”
4 - INSPECTION. The state or local gas inspector of the
side wall, horizontally vented, gas-fueled equipment
shall not approve the installation unless, upon inspec
tion, the inspector observes carbon monoxide detec
tors and signage installed in accordance with the pro
visions of 248 CMR 5.08(2)(a) 1 through 4.
EXEMPTIONS: The following equipment is exempt
from 24 CMR 5.08(2)(a) 1 through 4:
1 - The equipment listed in Chapter 10 entitled “Equip
ment Not Required to Be Vented” in the most current
edition of NFPA 54 as adopted by the Board; and
2 - Product Approved side wall, horizontally vented, gas-
fueled equipment installed in a room or structure sepa
rate from the dwelling, building or structure used in
whole or in part for residential purposes.
MANUFACTURER REQUIREMENTS GAS EQUIPMENT VENTING SYSTEM PROVIDED.
When the manufacturer of Product Approved side wall,
horizontally vented, gas-fueled equipment provides a vent
ing system design or venting system components with the
equipment, the instructions provided by the manufacturer
for installation of the equipment and the venting system
shall include:
1 - Detailed instructions for the installation of the venting
system design or the venting system components:
and
2 - A complete parts list for the venting system design or
venting system.
MANUFACTURER REQUIREMENTS GAS EQUIPMENT VENTING SYSTEM NOT PROVIDED.
When the manufacturer of Product Approved side wall,
horizontally vented, gas-fueled equipment does not pro
vide the parts for venting the flue gases, but identifies “spe
cial venting systems,” the following requirements shall be
satisfied by the manufacturer:
1 - The referenced “special venting system” instructions
shall be included with the appliance or equipment
installation instructions; and
2 The “special venting systems” shall be Product Ap
proved by the Board, and the instructions for that sys
tem shall include a parts list and detailed installation
instructions.
A copy of all installation instructions for all Product
Approved side wall, horizontally vented, gas-fueled
equipment, all venting instructions, all parts lists for
venting instructions, and/or all venting design instruc
tions shall remain with the appliance or equipment at
the completion of the installation.
Page 58
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